Environmental Impact Statement

   

 

 

 

 

 

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Draft Environmental Impact Statement

Fact Sheet

Project Title

Spokane County Wastewater Facilities Plan.

Project Description

Spokane County proposes to expand its existing wastewater treatment facilities to provide additional capacity for projected growth in the County and for increased wastewater flows generated by the County's Septic Tank Elimination Program.  This Spokane County Wastewater Facilities Plan Draft Environmental Impact Statement (EIS) provides a programmatic level of environmental analysis for the proposed treatment facilities.  Site-specific environmental review will be conducted prior to construction.

The expanded facilities will provide wastewater treatment for the County's Spokane Valley and North Planning Areas.  The County currently has an agreement with the City of Spokane to send 10 million gallons per day (mgd) to the City of Spokane's Advanced Wastewater Treatment Plant (SAWTP).  The County proposes to construct additional facilities to provide a total of 22 mgd of capacity.

The County is considering five alternatives in this Draft EIS.  The five alternatives are:

1.      Continue to send all County wastewater to an expanded SAWTP.  This alternative would require expansion of the SAWTP and a new interlocal agreement between the County and City.

2.      Add a new County plant in the Spokane Valley east of the City of Spokane.  Additional capacity would be provided by a new 12 mgd plant.  The County would continue to send up to 10 mgd to the SAWTP.

3.      Add a new County plant in the south-central part of the City of Spokane.  A new 12 mgd plant would provide additional capacity while the County would continue to send up to 10 mgd to the SAWTP.

4.      Build two new plants in the Spokane Valley.  Under this alternative the County would construct a 7 mgd plant and a  5 mgd plant in the Mid-Valley area.  The two smaller plants would be located close to where wastewater is generated and where the treated effluent could be sent to reuse applications.  Flows from North Spokane and a portion of the flow from the Spokane Valley would continue to be sent to the SAWTP.

5.      No Action, which would result in no expansion of wastewater treatment facilities.  Under this alternative the County would reach its 10 mgd allocation at the SAWTP by 2006 or 2007.  This alternative could lead to a moratorium on new development and to delay or cancellation of the County’s septic tank elimination program.

 

In addition to the proposed alternatives for treatment facility expansion, the County is considering alternatives for other system components.  These include demand management, effluent end use, and biosolids management.  The alternatives being considered for these system components are:

1.      Demand Management

·         Water conservation

·         Infiltration and inflow control

·         Industrial requirements for reducing wastewater strengths and flows

2.      Effluent End Use

·         Surface discharge and streamflow augmentation

·         Irrigation of poplar farms

·         Irrigation of urban greenspaces

·         Irrigation of agricultural land

·         Industrial reuse

·         Wetlands creation or enhancement

·         Groundwater recharge

3.      Biosolids Management

·         Class B treatment and land application

·         Class A treatment and land application

·         Composting

·         Treatment at City of Spokane facility

·         Co-incineration with solid waste

·         Privatized management

Action Sponsor and Lead Agency

Spokane County Public Works

1026 West Broadway Avenue

Spokane, WA  98260-0430

Contact Person

Bruce Rawls, Utilities Director

(509) 477-3604

Permits and Licenses Required or Potentially Required

Applicable permits will be applied for at a later date when individual projects are proposed.

 

Authors and Contributors

This programmatic EIS has been prepared under the direction of Spokane County Public Works Department, Utilities Division.  Research and analysis were provided by:

Adolfson Associates, Inc.

5309 Shilshole Avenue NW, Suite 200

Seattle, WA  98107

206-789-9658

 

HDR Engineering, Inc.

500 108th Avenue NE, Suite 1200

Bellevue, WA  98004-5538

Date of Issue

November 5, 2001

End of Comment Period

December 10, 2001.  Written comments should be directed to:  Bruce Rawls, Utilities Director, Spokane County Public works, 1026 West Broadway Avenue, Spokane WA  98260-0430.

Distribution

Copies of this document have been sent to the agencies, individuals and libraries listed in Section 5.  Additional copies are available for purchase at the Spokane County Public Works Department.

Website Access

This document may be viewed on the Spokane County Utilities Division website, www.spokanecounty.org/utilities/.  Click on the icon for Wastewater Facilities Plan.

Additional Environmental Review

Facilities constructed or expanded will be subject to project-level environmental review under SEPA prior to final design, permit approval, and construction.  A project-level Environmental Impact Statement addressing the alternative selected by the Board of County Commissioners is expected to be prepared in 2002.

Additional Copies

Copies of this document have been printed and made available for distribution.  Copies are available for review or purchase at the Spokane County Public Works office, Utilities Division, located at 1026 West Broadway Avenue.  Purchase price is $15.  Copies are also available for review at the Spokane County Public Library. 

 

TABLE OF CONTENTS

Fact Sheet   i

TABLE OF CONTENTS.. i

1.0           Purpose and need for the project.. 1

1.1       Introduction.. 1

1.2       Need for the Project.. 1

1.2.1     Background. 1

1.2.2     Purpose of the Project 9

1.3       Summary of Impacts. 9

1.4       Future Environmental Review... 9

2.0           Description of Alternatives.. 14

2.1       Introduction.. 14

2.2       Description of Alternatives for Wastewater Treatment Plants. 14

2.2.1     Alternative 1 — Continue to Send all County Wastewater to an Expanded Spokane Advanced Wastewater Treatment Plant. 14

2.2.2     Alternative 2 — Add a New County Plant in the Spokane Valley East of the City of Spokane. 15

2.2.3     Alternative 3 — Add a New County Plant in the South-Central Part of the City of Spokane. 15

2.2.4     Alternative 4 — Build Two New Plants in the Spokane Valley. 15

2.2.5     Alternative 5 — No Action. 16

2.3       Evaluation Criteria.. 16

2.3.1     Capacity. 16

2.3.2     Technical 16

2.3.3     Conveyance. 16

2.3.4     Implementation. 16

2.3.5     County Control 17

2.3.6     Regulatory. 17

2.3.7     Water Resource. 17

2.3.8     Impact 17

2.3.9     Economics. 17

2.3.10        Financial Risk. 17

2.3.11        Results of Evaluation. 17

2.4       Alternatives Considered but not Selected.. 18

2.5       Description of Alternatives for Other System Components. 19

2.5.1     Demand Management 19

2.5.2     Effluent End Use. 20

2.5.3     Biosolids Management 21

3.0           Impacts of alternatives and mitigation.. 23

3.1       Land Use. 23

3.1.1     Affected Environment 23

3.1.2     Impacts. 26

3.1.3     Mitigation. 27

3.2       Water Resources. 27

3.2.1     Affected Environment 28

3.2.2     Impacts. 38

3.2.3     Mitigation. 40

3.3       Environmental Health.. 41

3.3.1     Affected Environment 41

3.3.2     Impacts. 44

3.3.3     Mitigation Measures. 45

3.4       Plants and Animals. 45

3.4.1     Affected Environment 46

3.4.2     Impacts. 47

3.4.3     Mitigation. 47

3.5       Energy and Natural Resources. 47

3.5.1     Affected Environment 47

3.5.2     Impacts. 48

3.5.3     Mitigation. 49

3.6       Air Quality.. 50

3.6.1     Affected Environment 50

3.6.2     Impacts. 50

3.6.3     Mitigation Measures. 52

3.7       Transportation.. 52

3.7.1     Affected Environment 52

3.7.2     Impacts. 53

3.7.3     Mitigation Measures. 55

4.0           Other Systems Components.. 55

4.1.1     Demand Management 55

4.1.2     Effluent End Use. 55

4.1.3     Biosolids Management 58

5.0           References.. 62

6.0           Distribution List.. 1

 

Appendix A – Agency Correspondence

 

List of Tables

Table 1.  Effluent Quality Requirements for the City of Spokane Wastewater Treatment

Table 2.  Impacts Summary:  Treatment Plants and Conveyance Systems.

Table 3.  Impacts Summary: Demand Management, Biosolids, Effluent Reuse.

Table 4.  Evaluation Criteria Results.

Table 5. Anticipated Effluent Quality Requirements for New Surface Water Discharges for the Spokane River (Monthly Average Values Unless Noted Otherwise).

Table 6.  Sound Levels Produced by Common Noise Sources.

Table 7.  Maximum Permissible Environmental Noise Levels.

Table 8.  Electricity Requirements for Advanced Wastewater  Treatment Plants Without Nitrification.

 

List of Figures

Figure 1.  Vicinity Map 

Figure 2.  North Planning Area.

Figure 3.  Spokane Valley Sewer Project Priorities.

Figure 4.  Spokane Area Water Resources.

Figure 5.  Spokane Area Aquifers.

Figure 6.  Hydraulic Connectivity.

 

 


 

1.0                      Purpose and need for the project

1.1                         Introduction

This Environmental Impact Statement is written to assess the potential environmental impacts of Spokane County Utilities' Wastewater Facilities Plan (Plan).  The Plan is being developed to identify the wastewater facilities and programs that must be implemented to meet the long-term needs of the County.  The proposal to expand the wastewater treatment facilities in Spokane County is driven by a number of factors related to environmental protection, constraints on expansion of the existing treatment plant, population growth in the County, and the County's program to expand its wastewater collection system to reduce the number of septic tanks located over the Spokane Aquifer. This chapter describes the considerations for expansion of the wastewater treatment facilities and the County's objectives for a new treatment plant.  This chapter also summarizes the impacts anticipated from the County's proposed alternatives.

1.2                         Need for the Project

1.2.1                   Background

Spokane County is located in northeastern Washington adjacent to the Idaho border (see Figure 1).  The County population in 1999 was 414,000.  The largest city in the County is Spokane with a 1999 population of over 184,000.  The planning area for the Wastewater Facilities Plan is the urbanized area in the County immediately adjacent to the Spokane city limits to the north and east.  The North Spokane planning area is located along the Little Spokane River (see Figure 2).  The Spokane Valley planning area is located along the Spokane River adjacent to the city limits (see Figure 3).  The 20-year boundaries for these planning areas are defined by the  service boundaries between the County and the City of Spokane and Liberty Lake Sewer and Water District No. 1. The population of the planning area is 121,000 with over 58,000 currently served by the county sewer system. 

1.2.1.1               Water Quality and Water Resources Issues

Water quality and water resources issues in the planning area concern the Spokane and Little Spokane Rivers and the Spokane Valley-Rathdrum Prairie Aquifer.  The Middle Spokane River (the Spokane River from Nine Mile Bridge to the Idaho state line), the Little Spokane River, and Long Lake (the Spokane River from Upriver Dam to Lake Roosevelt) are all classified by the Washington State Department of Ecology (Ecology) for such uses as water supply; stock watering; fish and shellfish rearing, spawning and harvesting; wildlife habitat; primary contact recreation; and commerce and navigation.  Ecology has established water quality standards that must be achieved to maintain these designated uses.  Ecology has identified water quality problems in the Spokane River for the following constituents:  arsenic, cadmium, chromium, dissolved oxygen, lead, PCBs, sediment bioassay, and zinc.  Problem constituents in the Little Spokane River are fecal coliform, PCBs, pH, and temperature.  Continued use of the existing wastewater treatment facilities or construction of a new treatment facility will have to meet water quality standards established by Ecology to protect those characteristic uses of the water bodies and to minimize pollution problems from the identified constituents.

The Spokane Valley-Rathdrum Prairie Aquifer underlies the planning area.  This large aquifer is the primary source of drinking water for the Spokane Region.  Contamination of the aquifer threatens the drinking water supply of over 400,000 people.  Spokane County has been expanding its wastewater collection system to replace septic tanks since the 1980s.  The goal of this program is to reduce potential contamination of the aquifer.  The program is responsible for adding over 20,000 connections to the sewer system and anticipates an additional 20,000 connections by the time the program ends in 2015. 

1.2.1.2               Existing Wastewater Treatment System

Most of the wastewater in Spokane County is treated at the Spokane Advanced Wastewater Treatment Plant (SAWTP), owned and operated by the City of Spokane.  Spokane County maintains five small satellite treatment facilities.  These facilities are either community septic tanks or extended aeration package wastewater treatment plants.  The Liberty Lake Sewer and Water District No. 1 operates a treatment plant on the eastern edge of the Spokane Valley.

The SAWTP is located in northwest Spokane on the north bank of the Spokane River.  The 28-acre site is bounded by Riverside State Park.  The plant serves the City of Spokane, Spokane County, the Town of Millwood, the City of Airway Heights, and Fairchild Air Force Base.  The plant was constructed in 1958, expanded in 1962, and upgraded to provide advanced secondary treatment and seasonal phosphorous removal in 1977.  The plant has undergone several upgrades since 1977.  The rated capacity of the plant is 40 million gallons per day (mgd).  Spokane County has purchased 10 mgd of that capacity, as specified in an Interlocal Agreement between the County and the City.

The plant uses differing operation modes in the summer and winter because of more restrictive limits on phosphorous and ammonia-nitrogen in the summer.  During the summer permit season, the plant must provide at least 85 percent removal of phosphorous.  The summer season runs from June 1 to October 15, but can start earlier or extend later based on flow levels in the Spokane River.  Wastewater undergoes primary treatment, then enters an activated sludge treatment process.  During the summer permit season, alum is added to the wastewater flow prior to aeration to precipitate phosphorous.  The wastewater is disinfected by chlorination, with sulfur dioxide added to the final effluent for dechlorination. Treated wastewater is discharged to the Spokane River from a Parshall flume followed by a chute.  There is no subsurface outfall.  During winter months, plant operation is the same except that alum is not added to the wastewater flow.

 

Figure 1.  Vicinity Map

 

Figure 2.  North Planning Area

 

Figure 3.  Spokane Valley Sewer Project Priorities

 

 

The process for treating the solids generated by the wastewater treatment process is currently being modified.  The upgrades began in 1999 and are scheduled to be complete in 2004.  Treated biosolids are hauled from the treatment facility to offsite land application sites.  The biosolids are applied to agricultural fields in Spokane and Lincoln Counties.  In 1999, 7,515 dry tons of biosolids were applied to 2,603 acres. There is no seasonal difference in solids processing; however, when weather conditions do not permit transport biosolids are stored at the treatment plant. In the winter dewatered biosolids are stored in piles at the application sites for application when the ground thaws.  Liquid sludge storage is provided in digesters at the treatment plant when weather prohibits sludge haul.

The wastewater treatment facility operates under a National Pollution Discharge Elimination System (NPDES) permit issued by the Washington Department of Ecology (Ecology) in March 2000.  The effluent quality standards are summarized in Table 1.  Studies indicate that the SAWTP is generally in compliance with effluent requirements.  The city conducted a study of plant performance for the period 1997 to 1999 in comparison to the requirements of the March 2000 NPDES. Results of the review are summarized below:

·        Biological oxygen demand (BOD).  Mass discharge limits were met for the entire period.  Concentration limits and monthly percent removal requirements were met for the entire period with the exception of February 1999 when violations of the weekly concentration and percent removal requirements occurred.  The violations coincided with an upset in the activated sludge process believed to have been caused by introduction of a toxic material to the wastewater flow.

·        Suspended solids.  Mass discharge limits and percent removal requirements were met for the entire period.  Concentration limits were violated only in February 1999 for the weekly limit.  This episode corresponded with the process upset described for BOD.

·        Fecal coliform.  The SAWTP met monthly limits for the entire period, but experienced three violations of the weekly limit.

·        Ammonia-nitrogen.  These limits were met after the new aeration system was completed in August 1997.

·        Phosphorous.  The 85 percent removal requirement was met during each of the low-flow permit seasons.

·        Metals.  Limits for cadmium, lead, and zinc are based on historical performance of the SAWTP plus a 10 percent compliance buffer.  The SAWTP has complied with these limits.

The SAWTP is estimated to be operating at 88 percent of its nominal capacity rating.  In 1999, the average annual flow to the SAWTP was 39.5 mgd and the average dry season flow was 38.9 mgd. 

In the 1980s the City of Spokane initiated a sewer separation program that resulted in an 85 percent reduction of combined sewer outflow (CSO) discharges.  The city continues to have CSOs in frequencies that exceed state limits.

 

Table 1.  Effluent Quality Requirements for the City of Spokane Wastewater Treatment

Parameter

Low Flow Season (Jun - Oct)1

High Flow Season (Nov – June)1

Average Monthly

Average Weekly

Maximum Daily4

Average Monthly

Average Weekly

Average Daily4

Biochemical oxygen demand

(5 day)2

§          Concentration, mg/L

§          Mass, lbs./day

 

 

30

12,600

 

 

45

18,900

 

 

 

30

12,600

 

 

45

18,900

 

Total suspended solids2

§          Concentration, mg/L

§          Mass, lbs/day

 

30

10,530

 

45

15,795

 

 

30

10,530

 

45

15,795

 

Fecal coliform bacteria, #/100 ml

200

400

 

200

400

 

pH3

Daily minimum is equal to or greater than 6 and the daily maximum is less than or equal to 7.8.

Total ammonia (as NH3-N)5

§          Concentration, mg/L

§          Mass, lbs/day

 

1.61

591

 

 

6.33

2,290

 

5.3

591

 

 

13.4

13,522

Total chlorine residual

§          Concentration, μg/L

§          Mass, lbs/day

 

8.5

3.12

 

 

22.2

14.26

 

8.9

3.86

 

 

23.4

23.61

Phosphorus (total as P)

Monthly average of 85% minimum removal during the removal season6

Cadmium (total recoverable), μg /L

0.188

 

0.327

0.188

 

0.327

Lead (total recoverable), μg/L

1.98

 

3.18

1.98

 

3.18

Zinc (total recoverable), μg/L

60.55

 

82.20

60.55

 

82.20

               

SOURCE:  Spokane County Wastewater Facility Plan.  Basis of Planning Report, 2001c.

1      The average monthly and weekly effluent limitations are based on the arithmetic mean of the samples taken with the exception of fecal coliform, which is based on the geometric mean.

2      The average monthly effluent concentration of BOD5 and Total Suspended Solids (TSS) shall not exceed 30 mg/L or 15 percent of the respective monthly average influent concentrations, whichever is more stringent. When precipitation induced combined sewer over flow to the plant exceeds the maximum capacity of the secondary treatment portion of the plant for more than eight hours and results in the need for partial plant bypass, the influent and effluent values for the day may be excluded from the calculation of the average monthly percent removal. The daily values during the same event may also be excluded from the average weekly and monthly calculations for pounds of BOD5 and TSS. This exemption only applies under the conditions that all flow must receive at least primary treatment, all other permit conditions are met, and the plant discharge does not cause any violations of Water Quality Standards.

3      Indicates the range of permitted values. When pH is continuously monitored excursions between 5.0 and 6.0 or 7.8 and 8.5 shall not be considered violations provided no single excursion exceeds 60 minutes in length and total excursions do not exceed 7 hours and 30 minutes per month. Any excursion bellow 5.0 and above 8.5 are violations. The instantaneous maximum and minimum pH shall be reported monthly.

4      The maximum daily effluent limitation is defined as the highest allowable daily discharge. The daily discharge means the discharge of the pollutant measured during a calendar day. For pollutants with limitations expressed in units of mass, the daily discharge is calculated as the total mass of pollutant discharge over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the day.

5      There are no ammonia toxicity-based effluent limits when the Spokane River’s 7-day average flow is greater than 5000 cfs as measured at the Monroe Street Gage. As with all limits, new information can be cause for modification.

6      Seasonal chemical phosphorus removal must be initiated by no later than June, or terminate no earlier than October 15. The determination of variable spring initiation or fall termination of phosphorus removal outside the June 1- October 15 time period shall be made in accordance with the approved methodology and procedural guidelines contained in the Appendix. The monthly average shall be calculated using only the days when chemical removal is required.

1.2.1.3               Planning Area Population Growth

The total population served by the Spokane County wastewater treatment system was 53,318 in 1999.  That population is predicted to increase to 161,010 in 2020, triple the current population.  By 2050, the long-range planning period for the Wastewater Facilities Plan, the population is predicted to be 218,204, four times the current population.   These population figures were developed for the Year 2000 Comprehensive Wastewater Management Plan for Spokane County (CWMP).  The Growth Management Act mandates that urban service, including sewer service, must be available to serve this projected growth.  Projections indicate that the County will exceed its 10 mgd capacity at the SAWTP by 2006 or 2007. 

1.2.2                   Purpose of the Project

The objective of the Wastewater Facilities Plan is to identify viable alternatives for expansion of wastewater treatment facilities for Spokane County.  The following goals have guided the planning process:

·        Provide reliable wastewater service--both near-term (20 years) and long-term (50 years);

·        Protect public health;

·        Protect and improve the region's water resources--surface water and groundwater;

·        Provide cost-effective solutions for County ratepayers;

·        Provide for growth in concurrence with the Growth Management Act;

·        Ensure the County has adequate authority and control to meet future wastewater needs;

·        Gain approval by the public, elected officials, and regulatory agencies.

1.3                         Summary of Impacts

Potential impacts of the proposed alternatives for expanding wastewater facilities in Spokane County are presented in Chapter 3 of this Environmental Impact Statement.  The following matrix (Tables 2 and 3) summarizes those potential impacts.

1.4                         Future Environmental Review

This Environmental Impact Statement was prepared at a programmatic, non-project level.  It evaluates the potential impacts of the County's proposed alternatives for expanding wastewater treatment facilities.  Impacts evaluated include land use, water resources environmental health, plants and animals, energy and natural resources, air quality, and transportation.  The analysis did not include cultural resources because at this level of detail, a cultural resource evaluation would have been limited to a general discussion of cultural resources in the area.  In the future, a project level Environmental Impact Statement will be prepared to analyze the potential impacts of the alternatives sights that the County selects for the wastewater treatment facility.  The project level Environmental Impact Statement will evaluate siting details and site specific issues including cultural resources for each of the potential sites.


 

 

Table 2.  Impacts Summary:  Treatment Plants and Conveyance Systems

Element of the Environment

Alternative 1

All Flow to Expanded SAWTP

Alternative 2

New County Plant in Spokane Valley

Alternative 3

New County Plant in South-Central City

Alternative 4

Two New Plants in the Spokane Valley

Alternative 5

No Action

Land Use

·       Temporary construction-related impacts (e.g., increased noise, dust, construction vehicle traffic, traffic detours).

·       Land use impacts related to conveyance construction would be short-term, construction-related only.

·       Temporary construction-related impacts (e.g., increased noise, dust, construction vehicle traffic, traffic detours).

·       Conversion of existing land use(s) to utility use.

·       Potential land compatibility issues.

·      Siting within the City of Spokane would require a Special Permit.

·      Siting along the shoreline within the City of Spokane would require a Conditional Use Permit.

·       Same as Alternative 2.

·       Siting within the City of Spokane would require a Special Permit.

·       Siting along the shoreline within the City of Spokane would require a Conditional Use Permit.

·       Same as Alternative 2, but impacts would occur in two locations.

·       Possible building moratorium if treatment facilities are not expanded.

Water Resources

·       Construction near water bodies could generate increased runoff and sedimentation that could affect water quality.

·       The amount of effluent discharged to the Spokane River would increase.

·       Concentration of effluent in one reach of the river.

·      In areas with high groundwater tables, excavation could require dewatering.

 

 

·       Construction near water bodies could generate increased runoff and sedimentation that could affect water quality.

·       The amount of effluent discharged to the river would increase.

·       Greater dispersal of effluent with discharge below Upriver Dam.

·       Discharge into a gaining reach of the river with reduced potential for discharge to groundwater.

·      In areas with high groundwater tables, excavation could require dewatering.

·      Improved groundwater quality through continuation of the Septic Tank Elimination Program.

·      In water construction required to install new outfall diffuser.

·      Conveyance construction may require stream crossings.

 

 

·          Construction near water bodies could generate increased runoff and sedimentation that could affect water quality.

·          In areas with high groundwater tables, excavation could require dewatering.

·          Improved groundwater quality through continuation of the Septic Tank Elimination Program.

·          In water construction required to install new outfall diffuser.

·          Conveyance construction may require stream crossings.

·          Greater effluent dispersal than Alternative 1.

·       Construction near water bodies could generate increased runoff and sedimentation that could affect water quality. 

·       In areas with high groundwater tables, excavation could require dewatering.

·       Improved groundwater quality through continuation of the Septic Tank Elimination Program.

·       In water construction required to install new outfall diffuser.

·       Conveyance construction may require stream crossings.

·       Greater effluent dispersal from two plants.

·       If a new treatment plant were not constructed, the County would exceed its 10 mgd capacity at the SAWTP. 

·       The County would be unable to provide capacity for projected growth resulting in possible building moratoriums and/or fines for water quality violations.

·       Possible imposition of judicial control to regulate water quality.

·       The County would be unable to continue the Septic Tank Elimination Program.

Environmental Health

·      Construction-related noise (heavy trucks, machinery, worker's vehicles, voices) would occur during plant construction activities and during installation of the conveyance system and outfall.

·      Hazardous substances could be encountered during pump station or outfall construction.

·      Minor long-term noise impacts associated with plant operation.

·       There is potential for hazardous substance contamination on any given site; therefore a site assessment would need to be performed prior to any construction activity.

·       Construction-related noise (heavy trucks, machinery, worker's vehicles, voices) would occur for approximately 2 years.

·       Long-term operation-related noise similar to Alternative 1.

·      Hazardous substances could be encountered during pump station or outfall construction.

·       Same as Alternative 2.

·       Same as Alternative 2, but impacts would occur in two locations.

·       Water quality degradation could have health impacts.

Plants and Animals

·       Construction-related noise could cause birds and mammals to relocate.

·      Clearing and grading during construction would remove vegetation and potentially cause birds and small mammals to relocate.

·       Runoff and erosion during construction could reach waterways and impact fish habitat.

·       Operation-related noise could disturb some animal species.

·      Increased discharge and turbulence could cause fish and aquatic species to avoid the outfall area.

 

·       Same as Alternative 1.

·       Same as Alternative 1.

·       Same as Alternative 1.

·       If a new treatment plant were not constructed, and the SAWTP were not expanded, the county would exceed its 10 mgd

Capacity at the SAWTP. The County would be unable to provide capacity for projected growth resulting in degradation of water quality  and adversely impacting fish habitat.

Energy and Natural Resources

·       The major consumer of operation of energy during construction would be construction vehicles.

·       Construction would include consumption of fossil fuels, electricity, and possibly natural gas.

·       Operation of a wastewater treatment plant, pump stations, and motor-driven equipment would consume electricity. 

·       Two pump stations would be required under Alternative 1.

·       Methane gas would be produced during operation, which will be recovered as an energy source.

 

 

·       Same as Alternative 1; however, one to two pump stations would be required under Alternative 2.

·       Same as Alternative 2.

·       Same as Alternative 2.

·       Additional energy consumption would not occur under Alternative 5.

Air Quality

·       Construction would produce dust, asphalt fumes, and vehicle exhaust.

·       Odor will be produced during operation.  Significant odor producers will be covered, and odor scrubbing will be included as mitigation.

·       Worker's vehicles would produce approximately 18 trips per day.

·       There is potential for odor production at pump stations.

·       Same as Alternative 1.

·       Same as Alternative 1.

·       Same as Alternative 1.

·       If a new treatment plant is not constructed, the treatment capacity of the SAWTP would be exceeded and odor production could increase over time.

Transportation

·       Construction activities would add trucks and vehicles to the local streets, resulting in delays, congestion, and possibly detours.

·       During operation, biosolids transport from the facility would add approximately 3-4 heavy truck trips per day.

·       Construction of the conveyance system would result in temporary disruption to traffic flow, and possibly detours that could increase volumes on other roadways during the construction period.

·       Alternatives 1 and 3 include construction of forcemains through the City’s urban areas, increasing construction disruption.

·       Additional staff would be added if the existing SAWTP is expanded, adding additional vehicle trips to and from the site.

·       Construction activities would add trucks and vehicles to the local streets, resulting in delays, congestion, and possibly detours.

·       Approximately 18 vehicles trips per day would be generated by facility workers.

·       During operation, biosolids transport from the facility would result in up to approximately 3-4 heavy truck trips per day.

·       Construction of the conveyance system would result in temporary disruption to traffic flow, and possibly detours that could increase volumes on other roadways during the construction period.

 

·       Same as Alternative 2.

·       Alternatives 1 and 3 include construction of forcemains through the City’s urban areas, increasing construction disruption.

·       Same as Alternative 2.

·       No impacts to Transportation would occur under Alternative 5.

 


 

Table 3.  Impacts Summary: Demand Management, Biosolids, Effluent Reuse

Element of the Environment

Demand Management

Effluent End Use

Biosolids Management

Land Use

·      No impacts to land use are expected.

·      Potential discharge to poplar farm would convert land use at receiving site.

·      Irrigation of dry farm land could increase its property value.

·      Composting of biosolids would require approximately 20 acres and could pose siting problems.

Water Resources

·      The volume of effluent discharged could be slightly reduced.

·      Construction near waterbodies could generate increased runoff and sedimentation that could affect water quality.

·      No impacts to surface or groundwater quality expected because effluent would be treated and applied according to State of Washington standards.

·      No impacts to water resources are expected.

Environmental Health

·      No impacts to Environmental Health are expected.

·      No impacts to Environmental Health are expected because re-used effluent would be treated to Class C standards for poplar farm irrigation and Class A for all other uses.

·      Biosolids can contain microorganisms, trace metals, and organic compounds.  No impacts are expected because biosolids would be treated and applied in accordance with strict regulatory guidelines.

Plants and Animals

·      No impacts to plants and animals are expected.

·      No adverse impacts to plants and animals are expected.

·      Created wetlands could provide new or enhanced habitat

·      Application of biosolids generally enhances the growth and vigor of plants.

·      No impacts to wildlife are expected except where vegetation may be altered as a result of biosolids application.

Energy and Natural Resources

·      No impacts to Energy and Natural Resources are expected.

·      Some effluent end use options have significant energy requirements for pumping.

·      Reverse osmosis for groundwater recharge, if included in the selected alternative, is a very high energy user.

·      Some energy may be saved as a result of land application of biosolids because the use of chemical fertilizers that require large amounts of energy to produce would be reduced.

·      Transport of biosolids would consume energy in the form of vehicle fuel.

Air Quality

·      No impacts to air quality are expected.

·      Construction of the conveyance system to transport reclaimed water would produce dust, asphalt fumes, and vehicle exhaust.

·      Composting of biosolids produces significant odors requiring odor control measures.

·      Incineration of biosolids has the potential to create air quality pro-blems and would require air quality permits.

Transportation

·      No impacts to transportation are expected.

·      Construction of the conveyance system would result in temporary disruption to traffic flow, and possibly detours that could increase volumes on other roadways during the construction period.

 

·      Impacts to transportation would be limited to heavy trucks entering and exiting the treatment plant site to transport biosolids to application or disposal sites.

 


 

2.0                      Description of Alternatives

2.1                         Introduction

In the Spring of 2000, Spokane County Utilities began the process of developing a Wastewater Facilities Plan to identify wastewater facilities and programs that must be implemented to meet the long-term needs of the County.  Spokane County began the wastewater planning process to evaluate future County wastewater service areas, project future wastewater flows, and develop recommendations for new wastewater treatment facilities and reclamation programs. 

This chapter provides an overview and description of the alternatives being considered for expansion of Spokane County's wastewater treatment facilities.  The County is considering five alternatives for treatment facility locations and configurations.  In addition, the County is considering various alternatives for other system components including demand management, effluent end use, and biosolids management. The other system component programs are also presented in this chapter.  The evaluation criteria for screening the initial treatment facility alternatives and the alternatives considered but not selected are described.  In addition, this chapter describes the No Action alternative, as required by the Washington State Environmental Policy Act (SEPA).

2.2                         Description of Alternatives for Wastewater Treatment Plants

2.2.1                   Alternative 1 — Continue to Send all County Wastewater to an Expanded Spokane Advanced Wastewater Treatment Plant.

The Spokane Advanced Wastewater Treatment Plant (SAWTP) is operated by the City of Spokane.  The County has an interlocal agreement to send up to 10 mgd to the SAWTP.  This alternative would expand the existing SAWTP to handle all flows from the County and City through the year 2025.  The level of treatment would be upgraded to tertiary treatment.  The County's average flows in the year 2025 are projected to be 22 mgd with the combined City and County flows estimated to be 65 mgd.  The capacity of the SAWTP is currently rated at 40 mgd.    This Alternative would require a new interlocal agreement between the County and City.

This Alternative would require expansion of the County and City conveyance systems, especially the system that conveys flows from the Valley to the SAWTP.  The current interlocal agreement between the County and City sets the allowable peak flow through the City's interceptor system at 15.5 mgd.  Projected peak flows from the Valley are 37 mgd.  Conveyance of the amount of flow in excess of 15.5 mgd will require pumping through a new forcemain to the SAWTP.  This would require two new pumping stations and approximately 8 miles of forcemain.  The forcemain would be routed primarily through densely developed portions of the City.  Segments of the City's interceptor system would also need to be expanded in North Spokane.

2.2.2                   Alternative 2 — Add a New County Plant in the Spokane Valley East of the City of Spokane. 

This alternative would locate a new 12-mgd plant in the Spokane Valley east of the Spokane city limits.  Flows generated in the Spokane Valley would be sent to the new plant.  The new plant would provide tertiary treatment and would discharge treated effluent to the Spokane River below Upriver Dam.  The County would retain its current 10-mgd capacity allocation at the SAWTP and all flows generated in North Spokane and a portion of the flow from the Spokane Valley would continue to be sent to the SAWTP.  The County has identified this alternative as the Preferred Alternative.

The new plant most likely will be located along the North Valley interceptor and will require a new influent pumping station to lift the North Valley flow into the treatment plant.  A new pump station and force main will also be required to convey flow from the Spokane Valley interceptor to the new treatment plant.  This would substantially reduce the amount of flow conveyed from the Spokane Valley to the SAWTP.  This could reduce Combined System Overflows (CSOs) in the central portion of the City's conveyance system.  Some segments of the City's interceptor system would require replacement or the installation of parallel sewers to convey future North Spokane flows to SAWTP.

2.2.3                   Alternative 3 — Add a New County Plant in the South-Central Part of the City of Spokane.

Under this alternative a new 12-mgd plant would be constructed in the south-central area of Spokane, within the city limits.  This plant would provide tertiary treatment and serve flows generated in the Spokane Valley and the southern portion of the City's service area..  The County would retain its  10-mgd allocation in the SAWTP to handle flows from North Spokane and a portion of the flows generated in the Spokane Valley.  The new plant would be jointly operated by the City and County.

Because of the County's limited conveyance capacity in the City system, all flows sent to the new plant would be pumped through a new forcemain.  The forcemain would be constructed through developed portions of the City and would require the construction of pump stations.  

2.2.4                   Alternative 4 — Build Two New Plants in the Spokane Valley.

This alternative is similar to Alternative 2, but would construct two plants in the Mid-Valley area—a 5 mgd plant and a 7 mgd plant.  Both plants would provide tertiary treatment.  The two smaller plants would be located close to where wastewater is generated and where the treated effluent could be sent to reuse applications.  Flows from the North Spokane area and a portion of the flows from the Spokane Valley would continue to be sent to the SAWTP. The County would continue to send 10 mgd to SAWTP.

 

2.2.5                   Alternative 5 — No Action

Under this alternative, no wastewater treatment expansion would occur.  The County would continue to send all wastewater flows to the SAWTP plant up to its maximum 10 mgd agreement.  No new plant would be constructed and the SAWTP would not be expanded.  Under this alternative, the County would reach its 10 mgd allocation by 2006 or 2007. 

If the County takes no action to expand its wastewater treatment facilities, the permit requirements for discharge to the Spokane River could be violated and fines could be levied against the County.  No action could also result in a building moratorium and the imposition of judicial control over the County’s wastewater treatment program.

2.3                         Evaluation Criteria

In evaluating the alternatives for treatment plant facilities, Spokane County applied the following criteria.

2.3.1                   Capacity

This criterion addressed the ability of an alternative to meet the County’s near-term and long-term requirements for wastewater treatment capacity.  The near-term requirement relates to the ability to implement the solution before 2007, when County flows are projected to reach the capacity allocation in the SAWTP.  The long-term requirement relates to the alternative’s ability to provide a long-term (50-year) solution.

2.3.2                   Technical

This criterion considered the operational complexity of the alternative.  Since all alternatives would likely use similar treatment technologies, the number of plants and major pumping facilities that must be maintained primarily would affect the criterion.  Fewer facility requirements would result in a higher rating.

2.3.3                   Conveyance

This criterion considered the extent and complexity of sewers and pump stations that must be implemented.

2.3.4                   Implementation

Consideration was given to challenges associated with acquiring property and permits.  Generally, siting a North Spokane or In-City plant was considered more challenging than siting a Mid-Valley plant.  Also, siting multiple new facilities resulted in a lower rating.

2.3.5                   County Control

This factor relates to the County’s ability to implement the alternative on its own, without relying on actions by other jurisdictions.  This criterion is significant given the need to implement additional capacity by 2007.

2.3.6                   Regulatory

This criterion addressed anticipated impacts to the receiving streams and the potential for compliance with discharge permits.  Generally, alternatives that spread the location of effluent discharge along receiving waters were rated higher because they would lessen localized impacts.  Alternatives with multiple plants were rated lower because they would require compliance with more permits.

2.3.7                   Water Resource

This factor considered the proximity of the treatment plants to potential reuse opportunities.

2.3.8                   Impact

This criterion addressed the environmental and community impacts of building and operating wastewater facilities.

2.3.9                   Economics

This factor compared total life cycle costs, including capital and operating expenses.

2.3.10              Financial Risk

This factor considered the risk associated with the economic assumptions used in the analysis.  Alternatives that relied on other jurisdictions buying conveyance or treatment capacity from the County were rated lower.  Also, those alternatives that required other jurisdictions to participate in the financing of projects were rated lower.

2.3.11              Results of Evaluation

The final action alternatives were compared against an array of evaluation criteria using a modified "Consumer Reports" rating system.  The results are summarized in Table 4.  The No Action Alternative was not included in the evaluation because it does not involve any action from the County.

 

Table 4.  Evaluation Criteria Results

2.4                         Alternatives Considered but not Selected

Initially the County considered 13 wastewater treatment alternatives.  The 13 alternatives are variations of the four final alternatives described above.  The main components that vary in the alternatives are the size of the treatment plants and the amount of wastewater flows that would be sent to the SAWTP.  In addition, the initial alternatives considered construction of a 5 mgd plant in the North Spokane area to handle flows from the North Spokane Service Area. 

The size of treatment plants being considered under the initial alternatives ranged from 3 and 4 mgd to 17 mgd.  The size of the plants varied depending on other components of the alternatives.  Options for the amount of  wastewater flows to be sent to the SAWTP ranged from discontinuing all flows from the County to the SAWTP, to increasing County flows to the SAWTP to as much as 22 mgd.

Alternatives 2, 3, and 4 all initially included an option to construct a small plant in North Spokane with discharge to the Little Spokane River.  This option was considered as a means to handle flows from the North Spokane Service Area, and to beneficially recharge the Little Spokane River.  This option was eliminated from consideration because of complications associated with discharging effluent to the Little Spokane River, a limited number of suitable sites, and major costs associated with changing the conveyance system.

2.5                         Description of Alternatives for Other System Components

In addition to the alternatives considered for treatment plant locations and configurations, the County is considering different alternatives for other components of wastewater treatment, including demand management, effluent end use, and biosolids management.  The alternatives are presented below.  These system components are intended to be used in combination with the alternatives for treatment plants to improve wastewater management in the County.  It is likely that the alternatives selected for these system components will be a combination of the options presented below.

2.5.1                   Demand Management

Demand management is the package of efforts designed to reduce the quantity and/or strength of wastewater from the North Spokane and Spokane Valley service areas.  If demand management strategies are successful, the size of treatment facilities could be reduced and costs lowered.  Spokane County already has important demand management measures in place, including a ban on phosphorous-containing detergent, an industrial pretreatment program, effective control of infiltration and inflow, and a requirement that new construction or major remodels use low volume plumbing.  The County is considering the following alternative measures to further reduce wastewater flows.

2.5.1.1               Demand Management Alternative 1 — Water Conservation

A water conservation alternative would include a public education component to encourage people to use less water in daily activities.  The program would be continuous to help maintain conservation goals.  A second component of the water conservation element would be a plumbing fixture replacement program to encourage replacement of old plumbing fixtures.  This component could be accomplished through public education, economic incentives, and coordination with other agencies, organizations, and businesses.  A third component of the water conservation element would be an inverted rate structure for public water supply that would charge consumers a higher unit cost for any water consumed above a base amount.

2.5.1.2               Demand Management Alternative 2 — Infiltration and Inflow Control

This alternative would reduce the amount of water that enters the sewer lines by infiltration from groundwater or inflow from stormwater runoff.  One component of this alternative would be the elimination of basement sump pump discharges to sewers.  In areas of the County with high groundwater tables, the County would use public education and limited technical assistance to inform the public of the requirement to eliminate basement sump pump flows from the sewer system.  Another component of the alternative would be the review of codes, inspection and enforcement requirements to ensure that future construction would produce minimal contributions of infiltration and inflow. 

2.5.1.3               Demand Management Alternative 3 — Industrial Requirements for Reducing Wastewater Strengths and Flows

This alternative considers measures to further reduce the strength of industrial wastewater flows.  One component would be County review of ordinances to determine if increased requirements to minimize industrial wastewater quantities and strengths are needed.  Another component of this alternative would be to implement increased rates or surcharges for industries or businesses discharging high strength wastes.  The County is also considering establishing requirements or incentives to encourage industries to maximize water recycling and reuse within their operations.

2.5.2                   Effluent End Use

The County is considering the following alternatives for how treated effluent is returned to the environment or beneficially reused.  Under all alternatives the County would comply with state and federal guidelines and regulations for effluent reuse.

2.5.2.1               Effluent End Use Alternative 1 — Surface Discharge and Streamflow Augmentation

Under this alternative surface water discharge would continue for most effluent generated by the system.  Each of the five wastewater treatment alternatives assumes that the primary effluent end use strategy will be discharged to the Spokane River.  Surface water discharge could be used to augment minimum streamflows.  The approach includes a relatively low effluent conveyance cost, and simple effluent management requirements. Disadvantages of this approach would be limited reuse of the effluent and discharge of pollutants to the river during critical water quality periods.

2.5.2.2               Effluent End Use Alternative 2 — Irrigation of Poplar Farms

Under this alternative hybrid poplars would be irrigated with treated effluent.  Hybrid poplars have a high water demand during summer months and may produce revenue as pulp for paper or as a clear softwood.  Effluent for application would be treated to class C standards and conveyed 7 to 20 miles to county-owned land.

2.5.2.3               Effluent End Use Alternative 3 — Irrigation of Urban Greenspaces

This alternative would use treated effluent as an irrigation supply for golf courses, school grounds, parks, cemeteries, highway medians, industrial campuses, and other greenspaces.  Irrigation use of effluent would require construction of a distribution piping system and may require storage facilities to hold water until needed.  Irrigation of lands overlying the Spokane Aquifer may require additional treatment to reduce nitrate-nitrogen concentrations to acceptable levels for drinking water.  Use of effluent for irrigation would be limited to the summer irrigation season.  Effluent end use for irrigation could conserve groundwater currently used for irrigation and reduce effluent discharge to the river during the summer.

2.5.2.4               Effluent End Use Alternative 4 — Irrigation of Agricultural Land

Another option for effluent end use would be the use of effluent to irrigate agricultural lands.  This alternative would have similar advantages and disadvantages to the previous alternative.  If dryland areas were irrigated, there would be no reduction in groundwater consumption. This alternative could benefit dryland agriculture by allowing the production of higher value crops. 

2.5.2.5               Effluent End Use Alternative 5 — Industrial Reuse

This alternative would provide treated wastewater to industries for use as cooling water or in process applications.  This alternative would provide a year-round use for treated effluent and could conserve groundwater currently used by industries.  Industrial reuse may require high treatment costs to meet user needs and more complicated discharge permitting requirements.  In addition, there is the risk that the industry could relocate and/or change water requirements.

2.5.2.6               Effluent End Use Alternative 6 — Wetlands Creation or Enhancement

Treated effluent could be used to create constructed mitigation wetlands or as a reliable water source to restore degraded wetlands.  If the wetlands are located along streams, the water could also be used to augment streamflows after it is routed through the wetlands.  The advantages of this option include habitat creation, development of a wetlands bank in the County to facilitate economic development, and the potential to enhance stream discharge options.  The disadvantages would be a relatively low water demand, high land requirements for wetland construction, and the potential for adverse public perception of wastewater use over the aquifer.

2.5.2.7               Effluent End Use Alternative 7 — Groundwater Recharge

Effluent that was treated to a very high level could be used to recharge the groundwater supply.  This could be accomplished through surface percolation (spreading basins) or direct injection wells.  The water recharged to the aquifer could be withdrawn and used for any permitted use.  The advantages of groundwater recharge are maximum use of the effluent as a water resource, minimal discharge to streams, and recharge of the aquifer to provide an adequate water supply for present and future needs.  The major disadvantages are the high cost of treatment to drinking water standards, the potential adverse public perception of effluent discharge to the aquifer, and regulatory requirements.

2.5.3                   Biosolids Management

Biosolids are the residual materials from wastewater treatment.  They contain organic matter and plant nutrients such as nitrogen and phosphorous.  Biosolids can make good soil amendments, but the quality must be managed to minimize the presence of trace toxic materials and disease-causing organisms.  Currently the biosolids produced at SAWTP are treated to Class B standards to destroy disease causing microorganisms, to reduce the organic content, and to reduce the water content.  The treated biosolids are trucked to agricultural lands west of Spokane and used as soil amendments.  The following options are being considered for managing biosolids.

2.5.3.1               Biosolids Alternative 1 — Class B Treatment and Land Application

This approach would be similar to the practice currently used at SAWTP, and is assumed to be the primary biosolids strategy for each of the five wastewater treatment alternatives.  Biosolids would be digested, dewatered and transported for land application.  The sites for land application could be agricultural land or disturbed mining areas.  The advantages of this alternative are beneficial reuse of the biosolids, relative low operational cost, well-established technology, and good demand.  The disadvantages would be limited end-uses for biosolids and the potential that future regulations could require higher levels of treatment. 

2.5.3.2               Biosolids Alternative 2 — Class A Treatment and Land Application

Under this alternative, the biosolids would be treated to higher Class A standards with a high-temperature treatment process prior to dewatering.  Biosolids treated to higher standards have greater opportunities for end use, greater acceptance by potential users, less space requirements for treatment facilities, and less susceptibility to future regulatory change.  The major disadvantages would be higher energy costs for treatment, operation of a more complex treatment process, and a greater need for odor control.

2.5.3.3               Biosolids Alternative 3 — Composting

Under this alternative, Class A standards would be achieved by composting the Class B biosolids.  The end product is well accepted by end users.  The treatment facilities are low technology and fairly easy to operate.  Disadvantages of composting are that it is relatively expensive, requires land areas and a higher level of dewatering than land application, and requires significant odor control measures.

2.5.3.4               Biosolids Alternative 4 —Treatment at City of Spokane Facility

This alternative would construct no biosolids treatment facilities at the new treatment plant sites (Alternatives 2, 3, or 4).  All biosolids would be conveyed to the SAWTP for treatment.  The biosolids could be conveyed by the interceptor pipe system or a separate pipeline.  This alternative would require smaller plant sites for the new plants and would consolidate all biosolids handling in one location.  The major disadvantages of this approach are increased liquid treatment costs at SAWTP, possible spillage of solids during CSO events if the solids are returned to the interceptor or high conveyance costs of constructing dedicated pipelines.  Under this alternative, the County would be dependent on the City for biosolids treatment and disposal and an agreement between the County and City would be required to implement the proposal.

2.5.3.5               Biosolids Alternative 5 — Co-Incineration with Solid Waste

This alternative would incinerate dewatered biosolids at the regional solid waste incinerator.  The advantages of this approach would be a high level of volume reduction and multiple use of a regional waste management facility.  The disadvantages would be air quality concerns and permitting issues, high energy costs, potential compatibility issues with the solid waste system, and failure to beneficially use the biosolids.

2.5.3.6               Biosolids Alternative 6 — Privatized Management

Under this alternative, the County would contract with a private vendor to manage the biosolids, with the vendor hauling the material to a processing site.  This approach is used in some places in the region, including ECO composting in Missoula, Montana.  The advantages of this approach are lower capital costs, reduced space requirements for treatment facilities, and simpler siting of new treatment plants.  The disadvantages would be high transportation costs, potentially higher operating costs, and increased risk through dependency on a private entity.

3.0                      Impacts of alternatives and mitigation

This chapter assesses the impacts of the proposed alternatives for expansion of wastewater treatment facilities in Spokane County.  The impacts of the alternatives for other system components are described in Chapter 4.  Based on results of the public scoping process, the assessment includes a discussion of impacts associated with the following elements of the environment:  land use, water resources, environmental health, plants and animals, energy and natural resources, air quality, and transportation.  This chapter describes the affected environment, construction and operation impacts, and appropriate mitigation measures for each of these elements.

3.1                         Land Use

This section describes the land use effects associated with construction and operation of wastewater treatment facilities, and the project's consistency with adopted land use plans and zoning codes.  Relevant land use regulations for Spokane County and the City of Spokane are described, including Comprehensive Plans, Zoning Codes, and Shoreline Programs. 

3.1.1                   Affected Environment

The portions of Spokane County being considered for wastewater treatment facilities are designated in a variety of land use classifications, including residential, commercial, industrial, mixed use, rural conservation, small track agriculture, and mineral land.  Most of the area near the Spokane city limits and near the Spokane River has been developed as residential, commercial, or industrial.  Areas further east and further from the river are less developed and are generally rural or agricultural.  The area within the city limits under consideration for a new wastewater treatment plant has been developed as residential, commercial, or industrial.

3.1.1.1               Policies and Regulations

The Washington Growth Management Act (GMA) of 1990 requires that cities and counties prepare comprehensive plans that conform with GMA goals and urban growth area designations, and with population projections developed under the GMA planning process.  In August 2001 Spokane County adopted a revised Comprehensive Plan based on revisions to the 1994 document, Countywide Planning Policies.   Spokane County prepared a draft and final Environmental Impact Statement on the Recommended Comprehensive Plan.  The revised Comprehensive Plan contains policies for capital facilities and utilities, including wastewater treatment facilities.

The City of Spokane adopted a revised Comprehensive Plan on May 21, 2001 (Johnston, 2001).  A Draft Comprehensive Plan and Draft Environmental Impact Statement (City of Spokane, 2000) and a Final Environmental Impact Statement for the Recommended Comprehensive Plan (City of Spokane, 2001a) were prepared in support of the revision process.  The revised Comprehensive Plan contains policies for capital facilities and utilities, including wastewater treatment facilities.  

The GMA requires that a comprehensive plan or development regulation must allow for the siting of an essential public facility.  The GMA directs counties to "provide for a cooperative interjurisdictional approach to siting essential public facilities of a countywide, regional or statewide nature consistent with the Countywide Planning Policies" (WAC 365-195-340.3b).  In 1996, the County approved the Growth Management Essential Public Facilities Technical Committee Report (Spokane County, 1996).  The report was submitted to all Spokane County jurisdictions for inclusion in their comprehensive plans. The report includes a Model Siting Process, an Interjurisdictional Consistency Review Process, and an inventory of existing essential facilities.  Sewage treatment facilities are included as an essential public facility of a regional/countywide nature.  The report is included as part of the 2001 Recommended Comprehensive Plan.

The Model Siting Process includes the following steps: 

·        Step One:  Identify the proposed project as an essential public facility.

·        Step Two:  Classify the facility as having a statewide, regional/countywide, or local significance.

·        Step Three:  Provide early notification and involvement of affected citizens and jurisdictions allowing for opportunities to comment on the proposal.  The nature of the factors making the facility difficult to site should be considered when determining the appropriate level and type of citizen participation in the siting process.

·        Step Four:  Applicants for statewide and regional/countywide significant facilities should provide an analysis of alternative sites considered for the proposed facility.

·        Step Five:  The proposed facility should be reviewed for impacts of the facility on regional growth planning concepts such as the urban nature of the facility, existing urban growth near the facility site, compatibility of urban growth with the facility, compatibility of facility siting with respect to Urban Growth Area boundaries, urban sprawl, economic development, and affordable housing.

·        Step Six:  Proposed essential public facilities should be reviewed for site development criteria including the time required for construction, property acquisition, control of onsite  and offsite impacts during construction, and expediting and streamlining necessary government approvals and permits if all other criteria have been met.

·        Step Seven:  The proposed facility should be reviewed to determine if the financial impact on the jurisdiction can be reduced or avoided. 

The siting of a new wastewater treatment plant, if recommended by the Board of County Commissioners, will be consistent with this process.

The Spokane County Wastewater Facilities Plan is consistent with the recently adopted Spokane County Comprehensive Plan.  The County’s Division of Planning and Utilities Division worked together closely to develop consistent projections for population, commercial and industrial growth within the County’s Sewer Service Area.  The estimates of population served by the County’s wastewater treatment facilities are based on population growth projections and include extension of service to existing populations in the County not currently served by sewers.  These areas have been identified for future connection to the County sewer system through the Septic Tank Elimination Program to protect water quality in the Spokane Aquifer.

Zoning Ordinances for both Spokane County and the City of Spokane direct development in the area (Spokane County, 1998).  Spokane County's Zoning Ordinance (Chapter 14) includes wastewater treatment facilities in its definitions of a Public Utility Distribution Facility and a Public Utility Transmission Facility.  Both distribution and transmission facilities are permitted in all residential zones.  In business, industrial, mining, and agricultural zones, distribution facilities are permitted.  Transmission facilities are permitted subject to the following conditions:

·        The utility company shall secure the necessary property or right-of-way to assure the proper construction, continued maintenance, and general safety to the properties adjoining the public utility transmission facility;

·        The facilities shall be compatible with the surrounding uses either by distance, landscaping, buffering, or design, as determined by the Zoning Administrator; and

·        The height of the structure above ground does not exceed 125 feet.

The City of Spokane allows sewage treatment plants in all zones by special permit.  According to Article IV: Special Uses, subsection 13.19.310: Uses by Special Permit in Any Zone, of the Spokane Municipal Code–Land Use (City of Spokane, 2001), a special permit can be granted by the hearing examiner in any zone subject to conditions and standards as deemed necessary by the examiner.

Spokane County's Shoreline Program was adopted in 1974 (Spokane County, 1974).  The program regulates development of shorelines within 200 feet of the ordinary high water mark of streams with flows greater than 20 cubic feet per second (cfs), and lakes, impoundments, and reservoirs larger than 20 acres.  A Shoreline Management Substantial Development Permit is required for any development within these shoreline areas.  Shorelines in Spokane County are classified in five categories:  Natural, Pastoral, Conservancy, Rural, and Urban.  Spokane County's Shoreline Program permits wastewater treatment facilities in all shoreline areas except Natural Areas.  Shoreline designations along the Spokane River east of the city limits are either Conservancy or Pastoral.  Wastewater treatment and disposal facilities permitted in shoreline areas must meet the following conditions:

·        Compelling reasons exist for the specific site selection;

·        Mitigation measures would prevent these facilities from degrading the shoreline area with odors, noise, and visual detraction;

·        Subsurface disposal of wastewater would be prevented;

·        Facilities would not obstruct or impede the flow of floodwaters; and

·        Facilities would be designed so that, if flooding occurred, they would be protected from damage and would continue to function.

The City of Spokane's Shoreline Master Program was adopted in 1975 and amended in 1977.  The program sets goals and policies, regulates activities, and authorizes a permit system in a 200-foot shoreline area adjacent to the Spokane River and Latah Creek in compliance with the State Shoreline Management Act.  In 1982 the City Council approved a Supplement to the Master Program containing revised use regulations and administrative procedures (City of Spokane, 1982).  Siting of wastewater treatment plants is allowed in shoreline zones as a conditional use.

3.1.2                   Impacts

3.1.2.1               Construction

During construction, nearby residents and businesses may experience temporary construction-related impacts, such as increased noise, dust, and construction vehicle traffic.  Traffic may be temporarily rerouted.  These impacts would be temporary and would cease upon completion of construction.

3.1.2.2               Operation

Direct Land Use Impacts.  Development of treatment plant facilities may require conversion of existing land uses to a utility use.  In addition, conversion of private property to a public use would remove this land from the tax rolls, and could have minor impacts on Spokane County's revenue stream.  Under Alternative 5, No Action, a moratorium on building would likely occur.  Design of the wastewater treatment facility would likely incorporate architectural treatment, landscaping, and/or buffering to minimize adverse impacts on the adjacent neighborhood, and may raise land use compatibility issues in some areas.  More information on impacts at specific sites will be available during the next phase of the wastewater planning process, after the County has selected its preferred system alternative.

Little or no effect on property values is expected as a result of Alternative 1 because this alternative is the expansion of an existing treatment plant.  The potential to impact property values is greater for Alternatives 2 through 4 since they include the siting of one or more new treatment plants.  The extent of impact, if any, will depend on the location selected for a new plant.  Additional information about potential plant locations will be developed following selection of a preferred alternative by the Board of County Commissioners.

Land Use Plan Consistency.  Wastewater treatment facilities are a permitted activity in all of Spokane County's zoning classifications.  The City of Spokane also permits such facilities in all of its zoning classifications by Special Permit granted by the hearing examiner.  The proposed wastewater treatment facility would be consistent with County plans at any proposed location, and would require a Special Permit from the City.  Siting a plant along the shoreline of the Spokane River east of the city limits would be a permitted activity under the County Shoreline Program.  Siting a plant along the shoreline within the Spokane city limits would require a Shoreline Conditional Use Permit under all shoreline designations.

3.1.3                   Mitigation

3.1.3.1               Construction

The following mitigation measures could be implemented to relieve construction impacts on residences and businesses near the treatment facility site:

·        Develop a traffic control plan to ensure continued vehicular access on streets in the project vicinity.

·        Restrict construction to daylight hours of weekdays to reduce noise impacts on nearby residents; in addition, muffler systems on heavy construction equipment should be kept in good working order to ensure maximum noise attenuation.

·        Employ approved dust control measures during the construction phase.  This could include spraying areas of exposed soils with water and/or palliatives as necessary to reduce visible dust emissions. Dust emissions from soil transport should be reduced by covering loads, wetting dry soil, and washing of construction vehicle wheels.

3.1.3.2               Operation

Construction of wastewater treatment facilities is permitted under County land use and shoreline regulations and would not require any rezoning or comprehensive plan amendments.  If the plant were located within the Spokane city limits, it would require a Special Permit under City zoning laws and a Conditional Use Permit if located in the shoreline zone.  Project features such as odor control devices to reduce off-site odor impacts, visual screening of the facility with vegetation, and architectural treatment consistent with nearby structures or with a community-supported design theme would assist in maintaining compatibility with surrounding uses.  If public amenities are included within the facility's grounds (e.g., park-like use areas, trails, etc.), the local neighborhood could perceive the addition of public open space or recreation areas as a beneficial impact.

3.2                         Water Resources

This section describes the surface and groundwater resources of the project area and the existing water quality of those resources.  Surface and groundwater are discussed separately, but the two experience a high degree of hydraulic connectivity in the Spokane area.  Relevant federal, state, and local regulations are presented.  The regulations are presented first to establish the framework for the following discussions.   Impacts of each of the proposed alternatives on water resources and water quality are discussed.

3.2.1                   Affected Environment

Relevant Federal, State, and Local Regulations.  There are numerous federal, state, and local regulations that apply to water management in the Spokane area.  Those most relevant to construction of new wastewater treatment facilities are discussed here.

Clean Water Act.  The federal Clean Water Act (CWA) establishes the federal authority to set water quality and effluent standards to protect the nation's waters.  The CWA makes it unlawful to discharge any pollutant from a point source without a National Pollution Discharge Elimination Permit (NPDES).  The CWA is administered by the federal Environmental Protection Agency (EPA), but the authority for permitting, administration, and enforcement of provisions of the CWA has been delegated to most states.  The state of Washington has received EPA approval to administer the CWA provisions through the Department of Ecology (Ecology).  Ecology issues NPDES permits that define limits of discharges, and monitoring and reporting requirements.

Section 303(d) of the CWA requires each state to identify its polluted water bodies and submit the list to EPA every four years.  The 303(d) list identifies those water bodies that are water quality limited, or those water bodies that fall short of state surface water quality standards.  The CWA requires that states set priorities for cleanup of the 303(d) listed waters and establish cleanup plans.  One aspect of the cleanup process is the establishment of Total Maximum Daily Load (TMDL).  A TMDL is a calculation of the maximum amount of a pollutant that a water body can receive and still meet water quality standards, and an allocation of portions of that maximum amount to the sources that discharge that pollutant.  A TMDL is established for each pollutant that exceeds state standards.

Safe Drinking Water Act.  The federal Safe Drinking Water Act (SDWA) of 1974 establishes standards for drinking water supplies, including groundwater supplies.  Groundwater aquifers that serve as drinking water supplies can be protected by a "sole source" aquifer designation. A sole source aquifer is defined as an aquifer that supplies at least 50 percent of the drinking water to the area overlying the aquifer and in an area where physical, legal, or economic considerations limit the reliability of an alternative drinking water source (U.S. EPA, 2001).  The sole source designation is intended to protect such aquifers from contamination.  The primary mechanism for protection is the requirement that all proposed federal financially-assisted projects that have the potential to contaminate the aquifer be reviewed by the EPA.  Proposed projects that do not have any federal funding are not required to be reviewed by EPA.  The Safe Drinking Water Act was amended in 1996 to emphasize protection of drinking water sources through comprehensive watershed planning.  The amendments require states to develop a Source Water Assessment Plan that delineates source water protection areas, inventories contaminants in these areas and assesses the water system's vulnerability to these contaminants.  Information from the assessments must be made available to the public.

State Surface Water Quality Standards.  The Washington Department of Ecology classifies streams by water quality based on definitions in WAC 173-201A (Water Quality Standards for Surface Waters of the State of Washington).  The Middle Spokane River from RM 58.0 (Nine Mile Bridge) to the Idaho State line is designated as a Class A (excellent) stream.  Long Lake from Long Lake Dam to Nine Mile Bridge is classified as "Lake Class," and the Little Spokane River is classified as Class A.  The characteristic uses for these classifications are water supply, stock watering, fish and shellfish, wildlife habitat, recreation, and commerce and navigation.  Water quality in the rivers must comply with the water quality standards specified in WAC 173-201A. 

State Groundwater Quality Standards.  The Groundwater Quality Standards (WAC 170-200) are designed to protect the quality of all groundwater in the state in the saturated zone.  The standards include three mechanisms to maintain high groundwater quality.  Prior to discharge into any of the state’s waters, all known, available and reasonable methods of prevention, control, and treatment (AKART) must be employed.  The standards include an antidegradation polity to protect background water quality and to prevent degradation.  The standards also include criteria for the maximum concentration of specific contaminants.  The criteria are based on human health and welfare standards.

Minimum Flows.  The Department of Ecology is authorized to establish minimum streamflows on streams and rivers in the state.  These minimum flows are established to protect fish and wildlife, recreation, water quality, navigation, and aesthetics.  The minimum flows are established by administrative rule.   Ecology may not issue water rights that would reduce streamflows below those established for minimum flows, and Ecology may take enforcement actions against water users who withdraw water below the established minimum flows.

Watershed Planning.  In 1998, the state established a watershed planning process for designated Water Resource Inventory Areas (WRIAs) in the state (RCW 90.82).  The authorizing legislation was Senate Bill 2514, and the process is frequently referred to as SB 2514 planning.  The legislation provides grant funding for local governments to develop watershed plans for managing water resources and protecting existing water rights.  Each watershed unit must plan for water quantity issues and may opt to plan for water quality, fish habitat, and instream flows.

Water Quality Management Plan.  There are several groundwater protection programs in place in the Spokane area.  The Water Quality Management Plan is a program managed jointly by the City of Spokane and Spokane County.  The Plan, adopted in 1979, is intended to eliminate the major sources of contamination to the aquifer and restore its water quality.  Tools used to achieve these goals include 1) zoning ordinances and development restrictions, 2) a wastewater management plan, 3) stormwater management, 4) a critical materials ordinance, 5) and public education.  The program has successfully stopped the degradation of water quality in public water supply wells.  The success is largely attributed to the reduction in individual septic systems located over the aquifer.

3.2.1.1               Surface Water

Major Surface Water Bodies.  The major surface water body in the Spokane area is the Spokane River, which flows through the City of Spokane.  The major tributaries of the Spokane River are the Little Spokane River from the north and Latah (Hangman) Creek from the south. 

Spokane River.  The source of the Spokane River is Lake Coeur d'Alene in Idaho.  The river is approximately 111 miles long and drains an area of 6,580 square miles including the Coeur d’Alene and St. Joe Rivers.  The river flows in a westerly direction from the lake through the City of Spokane (See Figure 4).  Below the city, the river is dammed by Long Lake Dam to form Long Lake.  Below Long Lake, the river flows into the Columbia River at Franklin D. Roosevelt Lake, which backs up into the Spokane River.  There are five hydroelectric dams on the Spokane River between the Idaho border (RM 96) and Lake Roosevelt.  These dams are Upriver Dam (RM 79.9), Division Street Diversion Dam (RM 74.4), Monroe Street Dam (RM 73.9), Nine-Mile Dam (RM 57.6), and Long Lake Dam (RM 33.9).  Post Falls Dam in Idaho (RM 100.8) influences the hydrology of the Spokane River through the project area.  All of the dams but Long Lake Dam are run-of-river dams, not storage dams.  Run-of-river dams back up only enough water to establish a constant head for operation of the hydroelectric turbines.

The Spokane River experiences seasonal streamflow fluctuations, with flows peaking during spring snow melt and declining in late summer.  Typical streamflows range from less than 2,000 cubic feet per second (cfs) in August to 20,000 cfs in May or June (Spokane County, 2001c).  Historically peak flows have exceeded 45,000 cfs (USGS, 2001).  Low streamflows are a problem in summer and affect water quality.  During low flows, streamflows are regulated by operation of the Post Falls Dam, operated by Avista Utilities.  Avista's agreement with the State of Idaho to maintain the level of Lake Coeur d'Alene limits the amount of flow released to the Spokane River.  Ecology has recommended minimum flows for the Spokane River based on Washington Department of Fish and Wildlife recommendations, but they have not been adopted as an administrative rule.  The recommended flows are 2,000 cfs at the Spokane gage.

Little Spokane River.  The Little Spokane River flows into the Spokane River at Long Lake, approximately 5 miles north of the Spokane city limits.  The Little Spokane is headwatered in Pend Oreille County near Newport.  It is joined by the West Fork just south of the Spokane County border.  The lower segment of the Little Spokane River is designated as a state scenic river.  This designation is less strict than a federal Wild and Scenic River designation, but still places restrictions on activities near the designated segment, particularly for the location of dangerous waste management facilities or the discharge of any hazardous substances.

Streamflows on the Little Spokane are measured at the U.S. Geological Survey (USGS) gage at Dartford.  Streamflows typically range from 300 cfs to 700 cfs.  Summer flows on the Little Spokane are supplied almost completely by groundwater discharges to the river.  Summer flows in the river have been declining since the 1950s, due to surface and groundwater withdrawals and diversions (Washington Department of Ecology, 1995).  In 1975, Ecology closed the Little Spokane Basin to further water appropriations because of concerns about water availability and developed a management plan for the river.  All water rights issued since then have been conditioned to specific base flows.  A base flow of 115 cfs from July 1 to September 15 at the Dartford gage is established by administrative rule in WAC 173-555.  According to Ecology, streamflows at the Dartford gage do not meet minimum flow requirements approximately 15 percent of the time (Washington Department of Ecology, 1995).  Streamflows at the downstream Rutter Parkway gage are significantly higher because of recharge from the Spokane Aquifer.

 

Figure 4.  Spokane Area Water Resources

 
 

Latah (Hangman) Creek.  Latah Creek flows into the Spokane River on the west side of the city.  The creek originates in Idaho and flows northwest to the Spokane River.  Flows on Latah Creek fluctuate between a low of 30 cfs in summer to peaks of 2,000 cfs in winter.

3.2.1.2               Groundwater

Permeable soils and the glacial history of the area have created numerous groundwater aquifers in the area (See Figure 5).  The largest of these aquifers is the Spokane Valley-Rathdrum Prairie Aquifer (Spokane Aquifer), which extends from Lake Pend Oreille through the Spokane Valley.  Other aquifers in the area are the Deer Park Aquifer, the Little Spokane Aquifer, the Green Bluff, Peone Prairie, and Orchard-Pleasant Prairie Aquifers, and the East Columbia Plateau Aquifer.  The latter includes the West Plains Aquifer. 

Approximately 120 square miles of the Spokane Aquifer's 320 square miles is in Spokane County.  The aquifer is unconfined, with a seasonally fluctuating water table.  Recharge is primarily through infiltrating rainfall, hillside runoff from surrounding watersheds, leakage from the Spokane River between Post Falls and Sullivan Road, and leakage from Lake Coeur d'Alene and numerous other large lakes around the periphery of the Rathdrum Prairie.  Groundwater flow is generally from east to west.  Beneath the City of Spokane, the aquifer splits into two channels.  Most of the flow goes north through the Hillyard Trough to the Little Spokane River where it discharges through numerous springs and seeps.  The remaining groundwater flow moves through a narrow, gravel-filled channel in the bedrock just north of the Spokane River.  This groundwater flow discharges to a section of the Spokane River below Spokane Falls via several springs and seeps.

The Spokane Aquifer is the primary source of drinking water for more than 400,000 people in Idaho and Washington.  In 1978 the Environmental Protection Agency (EPA) designated the Spokane Valley-Rathdrum Aquifer as a "sole source" aquifer under authority of the Safe Drinking Water Act. 

Connectivity.  The Spokane-Rathdrum Prairie Aquifer is hydraulically connected to the Spokane and Little Spokane Rivers.  At times the rivers gain flow from the aquifer; at other times the aquifer gains flow from the rivers (see Figure 6).  The hydraulic connectivity significantly affects streamflows and the level of the aquifer and can affect water quality of both the aquifer and the rivers.  Connectivity is a key element in the evaluation of potential water rights for withdrawals from the Spokane Aquifer.

The Spokane River loses large quantities of water to the aquifer in the Spokane Valley.  Recent studies indicate that more than 140 cfs is lost to the aquifer between Post Falls Dam and Barker Road.  On the Little Spokane River, groundwater inflow to the river represents nearly the entire discharge to the river above the Dartford gaging station.  Below the Dartford station, streamflow increases due to groundwater inflow from the Spokane Valley-Rathdrum Aquifer.

Hydraulic connectivity is most significant during summer low-flow periods.  During summer it is estimated that up to 80 percent of streamflow in the Spokane River is aquifer discharge, whereas in the winter only 20 percent of streamflow is aquifer discharge (Miller, 1996).  There is still much uncertainty about the hydrology of the region and the amount of water exchange that occurs between the rivers and the aquifer.

Floodplains.  The Federal Emergency Management Agency (FEMA) maps flood prone areas for cities and counties based on calculation of the 100-year flood--a flood with a 1 percent statistical probability of occurring in any given year.  Major floodplains in the Spokane area are located along the shores of lakes, the Spokane River, and Little Spokane River. Within the planning area for the wastewater treatment plant, floodplain areas are limited to the area immediately adjacent to the Spokane River.

Lakes and Wetlands.  There are numerous lakes and wetland areas within the project area.  Major lakes include Newman Lake and Liberty Lake to the east and a cluster of lakes to the southwest, including Medical, Clear, and Silver Lakes.  Permeable soils limit the number of wetlands in the project area.  The lower reach of the Little Spokane River supports a high quality riparian wetland area.  Numerous wetlands and small lakes are located to the southeast of the City in the channel scabland area carved out by the glacial era Spokane floods.

3.2.1.3               Water Quality

Water quality issues in the Spokane area involve both surface and groundwater resources.  Several segments of the Spokane and Little Spokane Rivers have been placed on the federal Clean Water Act Section 303(d) list of impaired water bodies.  Because the Spokane Aquifer is unconfined, it can be easily contaminated.  Any contamination poses a threat to the sole source of drinking water for the region.

Water bodies are included on the 303(d) list because water quality does not meet state standards and technology based controls are inadequate to achieve those standards.  The Department of Ecology's (Ecology) 303(d) list for the Spokane River includes the constituents arsenic, cadmium, chromium, dissolved oxygen, lead, PCBs, sediment bioassay, and zinc.  Cadmium, lead, and zinc concentrations often exceed state water quality standards at the state border.  The source of these contaminants is attributed to the discharge of heavy metals at the Bunker Hill Superfund site on the South Fork Coeur d'Alene River, which discharges to Lake Coeur d'Alene.  Much of the metal loading reaching Washington is from the resuspension of sediment deposited outside the designated Bunker Hill Superfund site.  For 303(d) water bodies, the state must develop Total Maximum Daily Loads (TMDL) or maximum limits on the amounts of pollutants that can be discharged to a water body and allow that water body to meet water quality standards.  Ecology has established TMDLs on the Spokane River for phosphorous and metals (cadmium, lead, and zinc) and is considering a TMDL for dissolved oxygen in Long Lake and the Spokane River.  Segments of the Little Spokane River have been placed on the 303(d) impaired list for the constituents fecal coliform, PCBs, pH, and temperature.  No TMDLs have been established for the Little Spokane River.

 

Figure 5. Spokane Area Aquifers

 

 

Figure 6. Hydraulic Connectivity

 

Because of its sole source aquifer listing, water quality in the Spokane Aquifer has been monitored for over 20 years.  During this time, aquifer water quality has generally been good to excellent.  There have been less than 50 violations of drinking water standards.  During the mid 1980s, water quality declined slightly in terms of inorganic indicators like nitrate-nitrogen and chloride.  The decline was attributed to increased development and associated septic tanks and drainfields.  These water quality indicators improved steadily in the late 1980s and 1990s as sewer construction increased to replace septic tanks.  Septic tanks continue to be a contributor to local declines in water quality.  Other potential sources of groundwater contamination in the region have been identified and include stormwater injection through dry wells; chemical storage, transport, and accidental spills; improperly abandoned wells; leakage from underground pipelines and sewers; over-application and spillage of fertilizers; application of road de-icing compounds; leakage from above ground or underground fuel storage tanks and pipelines; improper waste disposal in excavations; sanitary landfills; and gravel pit mining.

Watershed Planning.  Three of four WRIAs covering the Spokane River Basin are involved in watershed planning. Watershed planning for the Middle Spokane and Little Spokane Rivers (WRIAs 55 and 57) is being conducted jointly.  Watershed assessment and development of a  water budget for the combined basins has begun.  Water quality, an optional planning component, is also being addressed in the watershed planning process for WRIAs 55 and 57.  Water quality is being evaluated as it relates to flows.

Latah Creek is located in WRIA 56.  The Latah Creek Planning Unit has completed the Phase 2 work plan and watershed assessment began in early 2001.  The Latah Creek Planning Unit has accepted the optional components of water quality, instream flow, and fish habitat.  No lead agency has been established for WRIA 54, the Lower Spokane River.

Proposed Water and Effluent Quality Standards.  A preliminary assessment has been made of likely effluent quality requirements for discharge of wastewater to the Spokane River based on state water quality standards and seasonal characteristics of the river (Spokane County, 2001c).  These potential requirements are shown in Table 5.  Discharge requirements will be established by Ecology during the NPDES permitting process.  The permitting process requires the County to demonstrate that effluent discharge will allow the receiving waters to meet water quality standards. 

The summer low-flow period is the most critical for water quality; therefore, Ecology typically establishes seasonal permit limits for wastewater discharges.  The more stringent requirements are in summer.  The potential discharge requirements shown in Table 5 reflect the need for more strict requirements in summer. 

 

 

Table 5.     Anticipated Effluent Quality Requirements for New Surface Water Discharges for the Spokane River (Monthly Average Values Unless Noted Otherwise).

Parameter

Summer

Winter

BOD (mg/L)1

10-20

30

Total Suspended Solids (mg/L)

30

30

Ammonia-Nitrogen (mg/L)1,2

1-2

4-8

Total Nitrogen (mg/L)

No limit

No limit

Total Phosphorous (mg/L)1,3

0.3-0.6

No limit

Dissolved Oxygen (mg/L)1

>6.0

No limit

Fecal Coliform (cfu/100 mL)

200

200

Chlorine Residual (µg/L)2

~8

~ 8

pH (s.u.)4

6.0-7.8

6.0-7.8

Lead (µg/L)5

~ 2

~2

Zinc (µg/L)5

~ 60

~ 60

Cadmium (µg/L)5

~ 0.2

~ 0.2

SOURCE:  Draft Wastewater Facility Plan; Spokane County, 2001b.

1      Required value will be defined by dissolved oxygen TMDL process.

2      Required value will be defined by mixing zone study for toxicity.

3      Required value will be defined through negotiation with Phosphorous TAC.              

4      Instantaneous value.

5         Required value will be defined based on monitoring of actual effluent metals concentration.

3.2.2                   Impacts

3.2.2.1               Construction

All alternatives except the No Action Alternative would have similar construction related impacts to water resources.  Alternative 5, No Action, would require no construction and thus would have no construction related impacts.  Alternative 1 would require construction near the river to expand the existing SAWTP.  Alternatives 2, 3, and 4 would require construction of new plants on new sites.  Construction impacts to water resources at these location(s) would depend on the proximity of the sites to surface water bodies.  If the plant location(s) are near surface water bodies, construction could generate increased runoff and sedimentation that could affect water quality.  It is likely that construction of a new outfall for discharges to the river will be required for Alternatives 2, 3, and 4.  New outfall construction will require in-water work, and could affect water quality during construction.  Because of the depth to groundwater, it is unlikely that construction of the new treatment plants or expansion of the SAWTP would require dewatering.

Alternatives 1 through 4 would require the construction of additional conveyance facilities.  Alternative 1 will require the largest amount of construction to install an 8-mile forcemain and two pumping stations through an urban area.  Conveyance facilities for Alternatives 2, 3, and 4 will also involve forcemain and pumping station construction, but on a smaller scale than Alternative 1.  Runoff from construction of these facilities could impact nearby water bodies. Conveyance construction for Alternative 1 will require a crossing of the Spokane River.  The river crossing work could require in water construction.

3.2.2.2               Operation

The wastewater treatment facilities proposed under all the alternatives could generate operational impacts on nearby water bodies.  Expansion of the SAWTP under Alternative 1 and construction of new treatment plants under Alternatives 2, 3, and 4 would increase the amount of effluent discharged to the Spokane River.  The County is considering alternatives that would reduce the amount of effluent discharged (See Section 3.9.2); however, the majority of effluent will be discharged to the Spokane River.  For all alternatives, effluent discharges would meet the standards of the NPDES permit negotiated with the Department of Ecology. 

It is anticipated that effluent quality requirements will be based on the requirements presented in Table 5, but will be refined based on the exact location of the discharge, results of mixing zone studies, effluent concentrations of metals, results of a dissolved oxygen TMDL Study, and negotiations with the Phosphorous Technical Advisory Committee.  Preliminary modeling indicates that near-field dissolved oxygen (DO) levels will be 0.2 mg/L or less.  This level of impact is allowable in stretches of the river where natural conditions prevent instream water quality from being met.  The stretch of river being considered for the discharge point has a naturally low level of DO from groundwater recharge.  The effluent discharge will not violate temperature criteria.  The water quality criteria for lead, cadmium, and zinc are already exceeded on the Spokane River.  The County anticipates receiving a performance based effluent limit to avoid worsening the condition.  In order to ensure that the metals concentrations in the effluent are low, the County will focus on identifying industrial discharge sources and requiring aggressive pretreatment to remove metals before discharges reach the County's waste stream.  The new plant will not use chlorine disinfection; therefore, there will be no chlorine toxicity problems.  Modeling indicates that the ammonia-nitrogen concentration will be below ammonia toxicity criteria.  The effluent is not expected to contain PCBs since the City of Spokane has not detected PCBs in the effluent from the SAWTP.  The assessment of far-field impacts will require more detailed modeling than can be performed at this time; however, it is anticipated that the new plant will produce low concentrations of DO consuming constituents such as biochemical oxygen demand (BOD) and ammonia.  The effluent will also contain low levels of phosphorous which can lead to primary production activity downstream. 

Alternative 1, expansion of the SAWTP, would concentrate effluent at one location on the river and could make meeting water quality standards difficult.  Alternatives 2, 3, and 4 would allow greater dispersal of effluent discharges.   Alternative 4 would provide the greatest effluent dispersal with the use of two smaller plants.  Alternative 2 would provide greater dispersal than Alternative 3 because it would be located at a greater distance from the SAWTP and effluent would be discharged in the section of the river below Upriver Dam.  Discharge to the reach below Upriver Dam provides several advantages over other discharge points on the river.  The reach is located on a gaining stretch of the river and would reduce the potential for discharge to the aquifer or migration of effluent into the aquifer.  This reach of the river provides good separation from the SAWTP discharge.  The reach is located downstream of the discharge points for Inland Empire Paper, Kaiser, and Liberty Lake, and would require consideration of those discharges in NPDES negotiations.

Under Alternative 1, the SAWTP site is projected to have adequate space for expansion to handle predicted wastewater flows through 2025.  The SAWTP will be expanded to 65 mgd in the 2020 horizon.  The site would then be at maximum capacity and could not be expanded on site to handle additional flows from the City or County.

Groundwater quality would improve under all the action alternatives.  Currently, wastewater is leaching into the aquifer though septic tanks.  The County’s Septic Tank Elimination Program requires increased treatment plant capacity to handle the increased volume of flows generated by new connection to the wastewater treatment system.  Alternatives 1 through 4 all provide expanded capacity and would allow the County to continue to improve groundwater quality through its Septic Tank Elimination Program.

None of the alternatives are expected to have significant impacts on water quantity in the Spokane River.  All the action alternatives would increase effluent discharges to the Spokane River by 34 cfs in 2025 and 42 cfs in 2050.  This is approximately 3 percent of the average summer flow of 1,400 cfs and an even smaller percent of winter peak flows.  The increased discharges are not expected to affect the hydrology of the river.

Construction in a flood-prone area could subject the treatment plant to damage that could make the plant inoperable during a flood event.  The treatment plant structures could also impede floodwaters and block flow, increasing flood damage.

Water quality impacts would be unacceptable under Alternative 5, No Action.  If no new treatment plant were constructed, the county would exceed its 10 mgd capacity at the SAWTP by 2007.  The County would be unable to provide adequate capacity for projected growth within the planning area.  This could result in building moratoriums, fines for violation of water quality standards, and possible imposition of judicial control to regulate water quality.  The County would also be unable to continue its Septic Tank Elimination Program.  This could result in declines in groundwater quality of the Spokane Aquifer.

3.2.3                   Mitigation

3.2.3.1               Construction

Construction of the wastewater treatment facilities could lead to increased erosion and sedimentation that could impact adjacent water bodies.  Erosion and sedimentation control measures suitable for the selected site would be included as part of project design and construction to minimize sedimentation.  Spokane County will require that a comprehensive erosion and sediment control plan be developed prior to construction.  At a minimum the plan would include elements for site stabilization, slope protection, drainageway protection, and sediment retention.  All construction activity would be required to use best management practices to minimize erosion and sedimentation impacts.  The project would also be required to comply with conditions of the NPDES general permit for construction issued by Ecology.  A spill control plan to prevent fuel, chemical, or other pollutant spills from reaching any surface water bodies or seeping into groundwater will be developed.  For any in water work, including stream crossings and installation of the outfall diffuser, the requirements of the WDFW Hydraulic Project Approval (HPA) will be implemented.

Dewatering may be required for construction of a new treatment facility or expansion of the existing SAWTP.  During construction, groundwater that might enter excavations and trenches would be controlled to protect the quality of foundations and fill materials.  To protect water quality in the Spokane Aquifer and any adjacent water bodies, groundwater collected from excavations would be drained to a stormwater treatment and collection system before discharge.  A dewatering plan would be developed to monitor groundwater withdrawal and avoid groundwater contamination.

3.2.3.2               Operation

The intent of the Wastewater Facility Plan is to improve water quality management in Spokane County.  Increased wastewater treatment capacity will prevent potential wastewater problems in the river and allow the County to continue its Septic Tank Elimination Program to prevent aquifer contamination. Effluent limitations will be set through negotiations with Ecology for the NPDES.  Operation of the treatment plant will enhance overall water quality.

Potential impacts, if the plant were to be located in a flood-prone area, could be mitigated by the following measures, some of which are provided as conditions of treatment plant construction in a shoreline area by the County Shoreline Program:

·        Locating as many of the treatment facilities as possible above the flood level;

·        Insuring that facilities do not obstruct or impede the flow of floodwaters; and

·        Designing facilities so that they are protected from damage and will continue to function during flooding.

3.3                         Environmental Health

3.3.1                   Affected Environment

This section discusses environmental health issues (e.g., noise, reuse of reclaimed water, and biosolids utilization) associated with the Spokane Wastewater Treatment Facility.

3.3.1.1               Noise

Noise sources in the Spokane Valley area consist of urban downtown, urban residential, suburban residential, and industrial.  The Interstate 90 (I-90) corridor is located approximately through the middle of the City of Spokane and contributes to the ambient noise levels in the vicinity.  There are two major railroad corridors through the City and the Mid-Valley.  More than 50 trains per day use the tracks and are a major source of noise.

Noise Overview.  The human ear responds to a wide range of sound intensities.  The decibel scale used to describe sound is a logarithmic rating system that accounts for the large differences in audible sound intensities.  This scale accounts for the human perception of a doubling of loudness as an increase of 10 decibels (dBA).  Hence, a 70 dBA sound level will sound twice as loud as a 60 dBA sound level.  People generally cannot detect differences of 1 dBA; under ideal laboratory conditions, differences of 2 or 3 dBA can be detected.  A 5 dBA change would be expected to be perceived under normal conditions.  Table 6 shows representative sounds and corresponding noise levels produced in decibels.

When addressing the effects of noise on people, it is necessary to consider the frequency response of the human ear.  Instruments are therefore designed to respond to or ignore certain frequencies.  The frequency-weighting most often used is A-weighting; measurements from instruments using this system are reported in “A-weighting decibels” or dBA.  All sounds in this discussion are reported in dBA. 

Factors affecting the impact that a given noise will have on a person include frequency and duration of the noise, the absorbency of the ground and surroundings, and the distance of the receptor from the noise source.  The receptor and the usual background noise levels also determine the degree of impact.

Relevant Local, State, and Federal Noise Standards and Guidelines.  Spokane County has not developed and adopted its own noise regulations.  The County follows the State of Washington noise regulations per WAC 173-60.  The following table shows the maximum permissible environmental noise levels based on the EDNA of a particular noise source.  EDNA is defined as "the Environmental Designation for Noise Abatement, being an area or zone (environment) within which maximum permissible noise levels are established."

Table 6.  Sound Levels Produced by Common Noise Sources

Thresholds/Noise Sources

Sound Level (dBA)

Subjective Evaluations

Possible Effects on Humans

Human Threshold of Pain
     Carrier jet takeoff (50 ft)

140

Deafening

Continuous exposure can cause hearing damage

Siren (100 ft)
     Loud rock band

130

Jet takeoff (200 ft)
     Auto horn (3 ft)

120

Chain saw
     Noisy snowmobile

110

Lawn mower (3 ft)
     Noisy motorcycle (50 ft)

100

Very Loud

Heavy truck (50 ft)

90

Pneumatic drill (50 ft)
Busy urban street, daytime

80

Loud

Normal automobile at 50 mph Vacuum cleaner (3 ft)

70

Speech Interference

Large air conditioning unit (20 ft) Conversation (3 ft)

60

Moderate

Quiet residential area Light auto traffic (100 ft)

50

Sleep Interference

Library Quiet home

40

Faint

Soft whisper (15 ft)

30

Minimal Effects

Slight Rustling of Leaves

20

Very Faint

Broadcasting Studio

10

Threshold of Human Hearing

0

Source:  US Environmental Protection Agency, 1971.

Note that both the subjective evaluations and the physiological responses are continuums without true threshold boundaries.  Consequently, there are overlaps among categories of response that depend on the sensitivity of the noise receivers.

Spokane County has established restrictions on noise levels during nighttime hours.  Spokane County Code restricts construction activities to the hours between 7 a.m. and 10 p.m. during which time construction noise(s) are exempt from the provisions of Section 6.10.010 – Noise Disturbances Prohibited. (Section 6.12.020 – Exemptions).  

The City of Spokane also follows the State of Washington Maximum Permissible Environmental Noise Levels (Table 7) and has restrictions on noise levels during specific time periods:

"No person may make or permit any unnecessary or unusual noise between the hours of 6 a.m. and 10 p.m. to the annoyance of others.  No person may make or permit, in the operation of a machine, in the harboring of an animal or otherwise, any noise between the hours of 10 p.m. and 6 a.m. to the annoyance of any other person of ordinary sensibilities" (Spokane Municipal Code, 10.08‑020 – Noise).

Table 7.  Maximum Permissible Environmental Noise Levels

EDNA of Noise Source

EDNA of Receiving Property

 

Class A

Class B

Class C

Class A

55 dBA

57 dBA

60 dBA

Class B

57

60

65

Class C

60

65

70

Source:  WAC 173-60-040

Hazardous Waste.  A review of hazardous waste site databases has revealed numerous hazardous waste sites, including Superfund sites, within the City of Spokane and Spokane County properties east of the city limits.  The databases reviewed include:

·        EPA's Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Information System CERCLIS

·        EPA's National Priorities List (NPL)

·        EPA's EnviroFacts Warehouse Web site databases

·        Ecology's Toxic Release Inventory (TRI)

·        Ecology's Resource Conservation and Recovery Information System (RCRIS)

Site-specific database searches and site assessments would be performed during the site selection process.

Some hazardous waste sites have leached contaminants to soils and groundwater, but contamination tends to be localized; in a few instances, the contaminated groundwater plume has migrated and poses a potential health hazard.  See the Groundwater Section for additional detail on groundwater contamination in the project area.

Reclaimed Water and Biosolids.  Reclaimed water and biosolids are discussed in Section 3.9.2, Effluent End Use, and Section 3.9.3 Biosolids Management.

3.3.2                   Impacts

3.3.2.1               Construction

Short-term impacts related to noise would be similar for Alternatives 2 through 4.  Construction noise would include excavation activities and machinery, heavy trucks, miscellaneous construction machinery (including pile drivers), and workers' vehicles.  Excavation activities would have the greatest impact to noise levels in the vicinity of the treatment plant construction.  Excavation would include digging and scraping of the soil by heavy machinery, and dumping of soil into the beds of heavy trucks for removal from the construction site.  Construction activities could last up to two years for the construction of a new treatment facility, with excavation activities occurring during the initial phase of construction.  Construction activities associated with expansion of the existing SAWTP (Alternative 1) would also last approximately two years. 

There is potential for the presence of hazardous substances on a given treatment facility site.  The degree of likelihood depends upon many factors, including previous uses.  A complete site assessment would be performed prior to commencement of any construction activity.  Impacts from hazardous substances for Alternatives 1 through 4 are not expected to be significant, because site remediation activities would occur prior to any construction.  No impacts associated with Alternative 5 would occur as no construction activities would take place.

Construction of a conveyance system would not be expected to encounter any hazardous substances because the conveyance routes will primarily follow existing roadways.  Roadway beds would have previously been examined during road and/or other utility construction.  Hazardous substances could be encountered during construction of pump stations or the outfall.   No long-term impacts associated with hazardous substances are expected for Alternatives 1 through 4 as a result of conveyance system, pump station, or outfall operation.

Conveyance system and outfall construction would result in short-term noise impacts to surrounding properties.  Noise sources would include heavy trucks and machinery, workers' vehicles, and voices.  The impacts to any given section would be temporary and short in duration, as construction activities move along the length of the route rather than remain in a single area.  Short-term noise impacts are therefore not expected to be significant.  No significant, long-term adverse impacts from noise are expected as a result of installation of a new conveyance system or outfall.  Some noise would be generated at pump stations, but is expected to be minor.  Pump stations would be housed in sound-proofed structures to minimize or eliminate noise.

The degree of significance related to noise impacts for all build alternatives would be dependent upon final site and conveyance route selection.  Noise impacts would be greatest in residential areas or where construction activities occur near a sensitive receptor (e.g., nursing home, school).

3.3.2.2               Operation

Long-term noise impacts associated with Alternative 1 would be similar to the existing conditions at the SAWTP facility.  Any increase in noise associated with an expanded treatment plant is expected to be negligible.

Long-term noise impacts associated with Alternatives 2 through 4 would be similar and would include workers' vehicles, heavy trucks for biosolids pick-up and disposal, on-site machinery, and voices.

Because any hazardous substances present on a given site would be removed and the site remediated prior to operation of a treatment plant, no long-term impacts associated with hazardous substances are anticipated.

The existing SAWTP uses chlorine for disinfection, sulfur dioxide for dechlorination, and alum for phosphorous removal and would continue to use these chemicals for up to 10 to 15 years.  Chemical disinfection will be replaced by UV disinfection within this 10 to 15 year period.  No significant adverse impacts are expected as a result of chemical use under Alternative 1.  

Alternatives 2 through 4 would incorporate UV disinfection as part of plant design.  A small amount of hypochlorite would be kept on site for process control functions.  Therefore, no significant adverse impacts are expected as a result of the use of chemicals for Alternatives 2 through 4.  Water quality degradation as a result of the No Action Alternative could result in environmental health impacts through increased discharges of toxic materials.

3.3.3                   Mitigation Measures

Mitigation measures for noise impacts would include housing noisy machinery in sound-proofed structures and keeping workers' vehicles and heavy trucks in good working order.  In addition, construction activities would occur between the allowable construction hours (6 a.m. to 10 p.m. for the City of Spokane, and 7 a.m. to 10 p.m. for Spokane County).

Mitigation measures associated with hazardous substances would include a thorough site assessment and remediation (if necessary) for a given site prior to commencement of any construction activities.

Use of hazardous substances at the treatment plant would occur in accordance with local and state standards and guidelines.  Transport, handling, and storage would comply with all applicable regulations to insure the safety of facility workers as well as residents or workers at nearby properties.  Material Safety Data Sheets (MSDS) would be made available to all employees at the treatment plant and appropriate training for anyone handling chemicals would be required.

Impacts and mitigation related to use of reclaimed water and biosolids are discussed in Section 3.9.2, Effluent End Use, and Section 3.9.3,  Biosolids Management.

3.4                         Plants and Animals

The following section describes the plants and animals in the project area with an emphasis on those that are listed as threatened, endangered, or candidate species by the state or federal government, and on state sensitive species.  Impacts of each of the proposed alternatives on plants and animals are discussed.

3.4.1                   Affected Environment

Habitat within Spokane County ranges from shrub-steppe in the lower scabland areas to subalpine mountainous area.  This habitat diversity supports a wide variety of plant species and wildlife.  The project area is located in the Urban Growth Area (UGA) surrounding the City of Spokane.  This area has been mostly developed, but contains small undeveloped areas. 

In 1996 Spokane County adopted its Critical Areas Ordinance (Spokane County Code 11.20) (Spokane County, 1996).  The Ordinance designated and mapped critical fish and wildlife habitat areas.  There are few Critical Areas within the County's draft UGA (Spokane County, Draft Comprehensive Plan 2000a).  Fish and Wildlife Critical Areas within the UGA include white tailed deer, urban natural open space, riparian areas, and wetlands.  The City of Spokane adopted its Critical Areas Ordinance in 1994. 

3.4.1.1               Threatened, Endangered, and Priority Species

Prior to construction of Grand Coulee Dam, several types of anadromous fish migrated through the Spokane River and spawned in the river and its tributaries.  Access to the Spokane River has been blocked since the 1940s.  Consequently, there are no threatened or endangered anadromous species in the project area. The Washington Department of Fish and Wildlife's (WDFW) Priority Habitat and Species (PHS) maps for the project area indicate that the Spokane and Little Spokane Rivers are priority habitats for resident fish (WDFW, 2001). The U.S. Fish and Wildlife Service (USFWS) list of threatened and endangered species for the project area does not list any fish species (USFWS, 2001).  See Appendix A for species letters.

The USFWS lists bald eagle (Haliaeetus leucocephalus), Ute ladies'-tresses (Spiranthes diluvialis), and water howellia (Howellia aqautilis) as threatened species that may occur in the vicinity of the project (USFWS, 2001).  In addition, Spalding's silene (Silene spaldingii) is proposed as a threatened species.  The PHS maps do not indicate that any of these listed species are located in the project area.  Bald eagles have been reported in the City of Spokane (City of Spokane, 1996).  It is unlikely that the listed plant species would be found in the project area; however, site specific surveys would be required.

The PHS maps indicate that priority habitat areas for the following species are found in the project area:

Bird Species:  merlin, osprey, peregrine falcon, pileated woodpecker, great blue heron, and mountain quail, and 

Butterfly species: Compton tortoiseshell and thicket hairstreak. 

The butterfly species are listed as monitor species by WDFW.  In general, the priority habitats for bird species are located along the Spokane River and the butterfly habitat is located in the hills north and south of the river.  One area of Compton tortoiseshell habitat is found along the river.  The mountain quail are located in upland habitat south of the Spokane River.

3.4.2                   Impacts

3.4.2.1               Construction

Construction related impacts would be the same for all the alternatives except Alternative 5, which would involve no construction and have no impacts.  All of the action alternatives, including expansion of the existing city plant under Alternative 1, would involve construction activities that could cause temporary disturbances to animal species.  Clearing and grading would remove vegetation and potentially cause birds and small mammals to relocate.  Similarly, construction related noise could cause birds and mammals to relocate during construction.   Construction could generate increased runoff and erosion from treatment plant areas.  If the sediment is allowed to reach waterways, it could impact fish habitat. 

3.4.2.2               Operation

Operational impacts of all the action alternatives on plant and animal species are expected to be minimal.  Each of the treatment plants will generate noise that could disturb animal species. Effluent discharges could degrade water quality in the Spokane River and adversely impact fish species, but effluent will be treated to meet Ecology’s specified permit limits.  The increased impervious surface created by construction of the treatment plant(s) could increase runoff to the river, but should not affect river hydrology because stormwater flows will be small relative to river flows.  The No Action alternative could impact aquatic species through water quality degradation.

3.4.3                   Mitigation

Potential mitigation measures for impacts to plant and animal species would include measures to reduce construction impacts and design measures to reduce operational impacts.  Prior to construction under any action alternative, each proposed site would be evaluated to determine the presence of threatened, endangered, or sensitive species.  Construction contractors would be required to follow best management practices to minimize noise and erosion.  A Temporary Erosion and Sedimentation Control Plan (TESCP) would be developed for construction.  The minimum amount of vegetation would be removed during construction and following construction, the treatment plant would be landscaped using native and/or exotic species.  The treatment plant would meet the water quality standard requirements of the NPDES permit.

3.5                         Energy and Natural Resources

This section discusses energy and natural resources issues (e.g., wastewater treatment facility components requiring energy resources) associated with the Spokane Wastewater Facility Plan.

3.5.1                   Affected Environment

Avista Utilities (Avista), formerly Washington Water Power, provides natural gas and electricity to the City of Spokane and outlying areas in unincorporated Snohomish County.  Avista receives electricity from the Bonneville Power Administration’s (BPA) federal power grid.  Electricity is also available through electricity generation facilities within city limits (Ehrbar, personal communication, 2001). Various private electricity distributors serve the greater Spokane area outside of the Urban Growth Boundary (UGB).

Increased energy capacity is anticipated to accommodate the City of Spokane Comprehensive Plan’s proposed future land uses.  Expansions will be required at existing substations located at Francis, Cedar, and Sunset, and new substations will be needed in Mead and the Indian Trail area (City of Spokane, 2000).

Wastewater facility components and/or processes that use electricity include pumping mechanisms, mechanical aeration, sludge processing systems, blowers, and solids-handling systems.  Motor driven equipment including pumps, fans, and compressors would also likely require additional energy sources.  In addition to these major electricity users, a variety of other plant, pump station, and accessory facilities require electricity.

3.5.2                   Impacts

3.5.2.1               Construction

All of the alternatives except for the No Action Alternative would have similar short-term impacts to energy during the construction phase.  With the expansion of the existing SAWTP (Alternative 1) or the construction of new wastewater treatment facilities (Alternatives 2, 3, and 4), the major consumer of energy will be construction vehicles that will require fuels during the construction and excavation phases.  Energy impacts associated with construction would include consumption of fossil fuels, electricity, and possibly natural gas.  Energy consumption would depend generally on the duration of construction.

3.5.2.2               Operation

Energy use for all of the alternatives will vary according to the capacity of each of the wastewater treatment facilities for Alternatives 1, 2, 3, and 4.  The effluent end use alternatives will have significant energy requirements associated with pumping.  Another high energy user in terms of the wastewater facility operation involves the alternatives that would use reverse osmosis for groundwater recharge.  Table 8 lists some of the components of a wastewater treatment facility and estimated electricity use by kilowatt-hours per day (kWh/d).

Because Alternatives 1, 2, 3 and 4 will all in effect discharge an average flow of 21.9 mgd, there is not a significant difference in energy use between these proposed alternatives. However, higher energy costs will be attributed to alternatives that require greater pumping.  Alternative 1 would require the construction of two new pump stations and Alternative 2 would require one new pump station.  Alternatives 3 and 4 would also require the construction of new pump stations; however, an exact number is unknown at the time of this document’s production.  Also, depending on the size of the wastewater treatment facility, energy efficiency (per mgd) would increase slightly as the plant size increases.


 

 

Table 8.  Electricity Requirements for Advanced Wastewater
Treatment Plants Without Nitrification.

Electricity Use, kWh/d

Item

5-mgd plant

10-mgd plant

20-mgd plant

Wastewater Pumping

716

1,402

2,559

Screens

2

2

3

Aerated Grit Removal

87

134

250

Primary Clarifiers

78

155

310

Aeration (Diffused Air)

2,660

5,320

10,640

Return Sludge Pumping

213

423

724

Secondary Clarifiers

78

155

310

Chemical Addition

290

552

954

Filter Feed Pumping

445

822

1,645

Filtration

247

385

709

Gravity Thickening

15

25

37

Dissolved Air Flotation

n/a

2,022

3,268

Aerobic Digestion

2,400

n/a

n/a

Anaerobic Digestion

n/a

1,400

2,700

Belt Filter Press

228

457

689

Chlorination

5

27

53

Lighting and Buildings

400

800

1,200

TOTALS

7,864

14,081

26,051

Unit Electricity Use (kWh/million gallons)

1,573

1,408

1,303

Water Environment Federation, 1997.

Under each proposed alternative, methane gas will be produced and will be recovered as an additional energy source.

Under all alternatives, most pump stations that will be in operation will be variable speed to facilitate flow variations without building large wetwells or causing flow surges to the treatment plant.  Well-designed variable speed systems are very energy-efficient.

Alternative 5, the No Action Alternative, would have the least impact on energy consumption in the project area.

3.5.3                   Mitigation

3.5.3.1               Construction

With either the expansion of the existing SAWTP (Alternative 1) or the construction of new wastewater facilities (Alternatives 2, 3, and 4), the use of energy efficient construction equipment could be required by the contractors.  This would include the use of the most fuel-efficient construction equipment. 

3.5.3.2               Operation

Many features that increase energy efficiency at a wastewater treatment plant can be incorporated or specified during plant design.  The County could require that these features be evaluated during the design phase.

3.6                         Air Quality

This section discusses the current air quality conditions in the City of Spokane and Spokane County area to the east of the city limits.  Applicable state and local regulations are summarized.  Impacts to air quality and mitigation associated with a new treatment plant facility are discussed.

3.6.1                   Affected Environment

Over the past 25 years, air quality in the City of Spokane has improved substantially from the heavily polluted situation in the 1970s.  However, Spokane is currently classified as a serious nonattainment area for carbon monoxide and a moderate nonattainment area for fine particulate matter (particulate matter up to 2.5 micron in diameter [PM2.5]) (Spokane County Air Pollution Control Agency (SCAPCA), 2001a).  According to the Department of Ecology's 1999 Air Quality Trends in Washington, the trend for carbon monoxide and fine particulate matter observations above federal standards has been a steady decline towards zero reports per year (Ecology, 1999).  According to SCAPCA's Air Quality Index information (SCAPCA, 2001b), there were only two days in 2000 where the air quality within Spokane County was rated as "Unhealthy for Sensitive Groups."  No Unhealthy, Very Unhealthy, or Hazardous days were reported for the year 2000.  As of February 2001, no unhealthy days have been reported in 2001 (SCAPCA, 2001b).

3.6.1.1               Relevant Local and State Air Quality Standards and Guidelines

SCAPCA has implemented an air quality maintenance plan to have the area redesignated from nonattainment to attainment status (SCAPCA, 2001a).  In addition, Spokane County has included air quality as a component of the Natural Environment chapter of its Comprehensive Plan.  This document sets goals and policies that are designed to maintain or improve visibility and air quality in Spokane County (Spokane County, 2000a).

3.6.2                   Impacts

3.6.2.1               Construction

Construction-related impacts to air quality would be generally the same for Spokane County wastewater treatment facility Alternatives 1 through 4.  Construction impacts would include dust from construction activities, asphalt fumes from paving operations, and vehicle exhaust from construction equipment, heavy trucks, and workers' vehicles.  People in passing vehicles, or residents or workers at nearby properties may detect odors at intermittent points during the construction period.  Because these impacts would occur intermittently during the allowable construction hours between 7 a.m. and 10 p.m. (Spokane County Code, Section 6.12.020, Exemptions) and for the period of construction only (approximately two years for Alternatives 1 through 4), they are not anticipated to be significant.  No construction impacts to air quality would occur as a result of Alternative 5.

Short-term impacts to air quality would include dust from construction conveyance system activities, asphalt fumes from paving operations, and vehicle exhaust from construction equipment, heavy trucks, and workers' vehicles.  People in passing vehicles, or residents or workers at nearby properties may detect odors at intermittent points during construction of the conveyance system.  Impacts would occur intermittently during the allowable construction hours between 7 a.m. and 10 p.m. (Spokane County Code, Section 6.12.020, Exemptions) and for the period of construction only. The conveyance system would be installed in segments, and would last approximately a week in any given segment.   Because impacts to air quality during installation of the conveyance system are short-term and temporary, they are not expected to be significant. 

3.6.2.2               Operation

Odor-causing substances that commonly occur in wastewater consist of both organic and inorganic compounds.  The compounds usually arise from biological activity in the wastewater collection and treatment system.  Most odor-causing compounds form as a result of anaerobic decomposition of organic material containing sulfur and nitrogen.

Odor emissions are most likely to occur during periods of increased ambient temperature and at points of turbulence within the collection and treatment processes.  The presence and direction of prevailing breezes and the proximity of homes or offices to the proposed treatment plant would influence the degree of impact, and impacts could vary as weather patterns change throughout the year.

Operational impacts associated with Alternative 1 would be similar to existing conditions.  The number of staff is expected to be approximately the same as described below for Alternatives 2 through 4 with approximately 18 vehicle trips per day.  A measurable increase in detectable odor emissions from the SAWTP under Alternative 1 is not expected since odor control would be provided as part of the expansion design.   Long-term impacts to air quality would be similar for Alternatives 2 through 4.  Impacts would mainly include odors from wastewater treatment, and would also include exhaust from equipment motors and worker vehicles.  Alternatives 2 and 3 would add one new treatment plant to the Spokane Valley area, and Alternative 4 would add two new treatment plants.  An additional treatment plant or plants could contribute odors to the Spokane Valley area.  Detectable odors are not expected to be significant due to odor control methods that will be incorporated into plant design.  Impacts to surrounding properties would depend upon final site selection, but would likely be greatest in a location near a residential area, and less in an industrial location. 

Long-term impacts to air quality as a result of operation of the conveyance system would generally be limited to emissions from workers' vehicles during inspection or maintenance activities.  There is potential for some odor production from pump stations due to an increase in turbulence at these locations.  Long-term impacts are not expected to be significant.

Treatment and conveyance of wastewater under Alternatives 1 through 4 could result in the release of volatile organic compounds (VOCs) or aerosols.  VOCs are compounds of carbon (excluding carbon monoxide, carbon dioxide, carbonic acid, metallic cabides or carbonates, and ammonium carbonate) which participate in atomospheric photochemical reactions.  Aerosols are very small airborne droplets that may be generated at aerated process points in a wastewater treatment plant and can be carried through the atmosphere.  Adverse impacts associated with VOCs and aerosols are not expected to be significant.  Pump stations and many treatment plant processes will be enclosed to prevent untreated dispersion of VOCs and aerosols to the outside environment.  The air drawn off the facility will be treated via a chemical scrubber or carbon treatment system prior to release.

3.6.3                   Mitigation Measures

Mitigation measures will be implemented to control dust and vehicle emissions during construction and control odor emissions during operation.  Construction mitigation would include such measures as wetting exposed surfaces, washing vehicles prior to leaving the project site, and shutting off engines when not in use.  Operation measures would include proper sizing of transport systems, and areas exposed to the atmosphere, servicing of odor control units, chlorination, and keeping equipment and vehicles in good working order to reduce emissions.

A variety of odor control measures may also be adopted to reduce or eliminate odors from treatment plant operations.  Typical odor-control measures used at wastewater treatment plants include collection of emissions followed by "scrubbing" to remove odors or other contaminants such as VOCs and aerosols, prior to release to the environment.  Process controls that optimize the breakdown of wastes in the wastewater stream can also reduce or eliminate serious odor problems.  In addition, the treatment facility would be sited to maximize the distance between the plant and nearby properties where feasible.  Some sites would allow a design that maximizes the buffer between the plant and affected properties, while other sites would be more constrained, limiting opportunities for buffer area between the plant and surrounding properties.

3.7                         Transportation

This section discusses the general transportation system in the City of Spokane and Spokane County.  Impacts to local street grids are discussed as well as potential mitigation measures.

3.7.1                   Affected Environment

The project area falls within the City of Spokane and unincorporated greater Spokane Valley  and consists of business, residential, and industrial areas.  The street grid in the vicinity of the Spokane Area Wastewater Treatment Plant (SAWTP) consists of both main arterials and side streets.  Interstate 90 (I-90) runs west to east and is approximately 3.75 miles south of the SAWTP; US 2/395 runs north to south and is approximately 3.25 miles east of the SAWTP.

The Spokane Valley lies to the east of the City of Spokane.  I-90 runs approximately east to west through the Spokane Valley (Refer to Figure 1).  SR-290 also runs approximately east to west through the valley and is paralleled by the Burlington-Northern Railroad line.  U.S. Highway 2 joins I-90 just west of Spokane and follows I-90 for a few miles before heading north.  U.S. Highway 395 follows the I-90 route until its junction with Highway 2.  Approximately six miles north of the junction, U.S. Highway 395 splits off to the northwest and Highway 2 heads north.  U.S. Highway 195, a major north-south highway through eastern Washington, follows the Latah Creek Valley and connects with I-90.  The street grid within the Spokane Valley consists of both main arterials and side streets within a mainly commercial and industrial mix of uses.

Numerous Spokane County Public Works projects are proposed (Spokane County, 2001a), some of which may coincide with construction of the Spokane Wastewater Treatment Facility project.  Public works projects include both road and utility construction or maintenance.  Coordination between Public Works and treatment facility construction projects would be important to minimize or eliminate transportation impacts in the project vicinity.

3.7.1.1               Relevant Local, State, and County Transportation Standards and Guidelines

The Spokane Metropolitan Area, Metropolitan Transportation Plan (1999) sets forth standards and guidelines for transportation planning in the City of Spokane and surrounding areas.  Policy Topic 5—Transportation of the Countywide Planning Policies for Spokane County (1998) sets forth policies and guidelines for regional transportation planning for Spokane County.  These policies are guided by the Growth Management Act (GMA), and encourage the coordination of land use plans and policies through the Spokane Regional Transportation Council (SRTC) to ensure they preserve and enhance the regional transportation system (Spokane County, 1998).

Spokane County has established Level of Service (LOS) standards for the county transportation system.  LOS for regional transportation is based on corridor travel time.  Spokane County's Comprehensive Plan (Spokane County, 2000a) has established LOS goals for transportation; the following goals are applicable to the proposed wastewater treatment plant project:

·        Goal T.8a   Establish and maintain level of service standards for roads.

·        Goal T.8d   Clean streets as needed to meet air quality standards for particulate matter (PM).

The City of Spokane has established a Level of Service Standard/Concurrency Management System (LOS/CMS) as part of its comprehensive planning efforts "to help manage growth and to assure that adequate transportation facilities are in place concurrent with new development" (City of Spokane, 2000; 2001a). 

3.7.2                   Impacts

3.7.2.1               Construction

Construction-related impacts to transportation would be generally the same for Alternatives 1 through 4.  Impacts would include movement of personal vehicles and heavy trucks into and out of the construction site. Both personal vehicles and heavy trucks would use the local street grid and would temporarily contribute to traffic volumes and possibly congestion in the area.  Construction activities are expected to last approximately two years.  During construction, approximately 50 heavy truck trips per day would occur.  Initially, truck trips would primarily consist of removal of excavated soil from the site.  As construction progresses, heavy trucks and/or trailers would also enter and exit the site to deliver or remove construction equipment and building materials.  Traffic would be periodically stopped along affected roadways to allow heavy, large trucks and trailers to move into and out of the site.  This could result in temporary delays for general purpose traffic.  As construction nears completion, the number of heavy trucks making deliveries would decrease, and the main traffic into and out of the site would be personal vehicles of construction workers.  Temporary traffic detours could also occur during construction, increasing volumes to other roadways and possibly increasing travel time for some motorists.  Due to the temporary nature of construction activities, no significant adverse short-term impacts to transportation are expected to occur.

Conveyance system construction would result in temporary disruptions to traffic flow during excavation, installation of pipe and pump stations, outfall construction, and roadway resurfacing activities.  Temporary traffic detours could also occur during construction, increasing volumes to other roadways and possibly increasing travel time for some motorists. 

Alternatives 1 through 4 would require the construction of additional conveyance facilities.  Alternative 1 would require the largest expansion of the conveyance system with construction of a new forcemain through urban areas and two new pumping stations.  The new forcemain would be approximately 8 miles long.  This could cause traffic disruptions over a large area and construction impacts such as dust and noise would impact businesses and residences.  Alternative 3 would also require construction of a new forcemain through an urban area.  This would have similar impacts to Alternative 1, but on a smaller scale since the forcemain would be shorter.  Alternatives 2 and 4 would also require construction of forcemains and pump stations, but the required conveyance facilities would be smaller and construction would occur in areas where construction would be less disruptive of traffic and businesses.

3.7.2.2               Operation

Operational impacts to transportation are expected to be minor because in general a wastewater treatment plant generates relatively few trips per acre.  Treatment plant workers' vehicles would enter and exit the site on a daily basis.  A new treatment plant could be staffed 24-hours per day, although automation may allow a plant to operate without on-site staff at night and on weekends.  Approximately five employees per 8-hour shift would work at the treatment plant.  Estimating approximately two car/truck trips per day per employee would result in approximately 18 trips per day.  Additional staff would be added under Alternative 1, resulting in an increase in the number of vehicle trips to and from this site.  Biosolids and other solid waste would be removed from the site on a daily basis.  Regular municipal solid waste would be picked up once a week.  Three to four heavy truck trips per day would be generated for biosolids transport.  The relative significance of the addition of these vehicle trips to local roadways would be dependent upon the final site selection and existing traffic and road conditions in the area. 

During final site selection, the transportation analysis will be able to be more specific about traffic impacts for alternative plant sites.

No long-term transportation impacts associated with operation of the conveyance system, pump stations, or outfall are expected. 

3.7.3                   Mitigation Measures

Mitigation measures for construction-related impacts would include signage alerting drivers to the presence of large construction vehicles, and flaggers to control traffic flow at and/or near the entrance to the construction site.  Because operational impacts are not expected to be significant, no long-term mitigation measures would be provided.

4.0                      Other Systems Components

4.1.1                   Demand Management

4.1.1.1               Affected Environment

Spokane currently has a number of demand management practices in place to reduce the quantity and/or strength of wastewater transported to the treatment facilities.  These measures include a ban on phosphorous-containing detergents, an industrial pretreatment program, effective control of infiltration and inflow, and a requirement that new construction of major remodels use low volume plumbing. 

4.1.1.2               Impacts

The proposed measures for demand management are not expected to impact any of the elements of the environment being considered in this EIS.  All of the measures are administrative and would not involve any construction.  Some of the measures could have economic impacts on utility customers who might have to pay more for water or retrofit their sump pump systems to eliminate discharges to sewers.

4.1.1.3               Mitigation Measures

No mitigation measures are proposed because no impacts are anticipated.

4.1.2                   Effluent End Use

4.1.2.1               Affected Environment

Reclaimed water has been used in the State of Washington since approximately 1997 when the State Legislature directed the Department of Ecology and the Department of Health to establish and administer a reclaimed water demonstration program (Ecology, 2000).  Reclaimed water uses include irrigation of food/non-food crops, landscaping/lawns, landscape impoundments, restricted and nonrestricted recreational impoundments, constructed treatment wetlands, groundwater recharge, commercial and industrial uses, and streamflow augmentation.  Washington State has four classes of reclaimed water that are classified by the level of treatment provided.  Class A reclaimed water receives the highest level of treatment while Class D receives the least amount of treatment above standard wastewater treatment levels.  All reclaimed water suitable for reuse undergoes treatment and disinfection generally over and above conventional wastewater treatment facilities.

Areas of concern have included the effects of reclaimed water on groundwater quality, particularly where it is used specifically for groundwater recharge, and health effects to humans who come into contact with the reclaimed water.

Spokane County is considering seven alternatives for effluent end use including streamflow augmentation; irrigation of a poplar farm, urban greenspaces, or agricultural land; industrial reuse; wetlands creation or enhancement; and groundwater recharge.  Refer to Section 2.5.2 for a description of effluent end use alternatives.

Relevant Local and State Standards and Guidelines.  The Washington State Department of Ecology has developed a set of standards and guidelines for reclaimed water use within Washington State.  This document, Water Reclamation and Reuse Standards (Washington Department of Health and Washington Department of Ecology, 1997), covers all aspects of reclaimed water use including allowable uses; methods of treatment; sampling and analysis; operational, design, reliability, and use area requirements; standards for wetlands; and standards for direct aquifer recharge.

4.1.2.2               Impacts

Construction.  Short-term impacts associated with reclaimed water use would be limited to the construction activities necessary to bring the water to a given site and the installation of an appropriate delivery system (e.g., sprinkler system).  These activities could include excavation, and noises associated with workers' vehicles and machinery.

It is anticipated that effluent intended for reuse would be transported to application areas via a subsurface conveyance system.  It is expected that the selected conveyance system route would primarily utilize existing roadways.  Conveyance system construction would result in temporary disruptions to traffic flow during excavation, installation of pipe and pump stations, and roadway resurfacing activities.  Temporary traffic detours could also occur during construction, increasing volumes to other roadways, and possibly increasing travel time for some motorists.  The extent of transportation impacts would depend upon the distance to the chosen re-use areas and the traffic volumes along the conveyance routes.  Conveyance for irrigation and wetland creation/enhancement would likely have a greater impact to transportation than the conveyance required for industrial uses, due to greater distances and the larger number of use areas.

Construction of the conveyance system would cause temporary increases in erosion and sedimentation to nearby water bodies.  The conveyance system may require stream crossings.  If the conveyance system is installed along existing roadways, there would be no impact to plants, but installation in unpaved areas would require clearing.  Construction noise and activities could temporarily displace animals.  Construction impacts to environmental health, energy, and air quality would be similar to those described in Sections 3.3, 3.5, and 3.6.

Operation.  As described above under Relevant Local and State Standards and Guidelines, reclaimed water would be treated in accordance with guidelines in the Water Reclamation and Reuse Standards (Washington Department of Health and Washington Department of Ecology, 1997). Reclaimed water intended for poplar farm irrigation would be treated to Class C standards.  Reclaimed water intended for all other uses would be treated to Class A standards.  Reclaimed water used for industrial reuse may receive additional treatment for color.  Water used for wetlands will also be treated for phosphorous and total nitrogen reduction and water used for groundwater recharge will be treated to Class A standards followed by reverse osmosis.  Any reuse would comply with the standards for specific use types as defined in Water Reclamation and Reuse Standards

Operational impacts related to the use of reclaimed water are not expected to be significant.  Water resource impacts would be minimized by following the state guidelines for reclaimed water (Washington Department of Health and Washington Department of Ecology, 1997).  No adverse impacts are expected as a result of agricultural or urban irrigation with Class A  effluent.  Class A effluent has received the highest level of treatment and is considered safe for all irrigation methods, including spray irrigation.  Poplar farm irrigation using Class B effluent is not expected to result in adverse impacts because no food products would be produced and the farm would not be used by humans for purposes such as recreation.  In addition, irrigation rates would follow irrigation requirements for crops in Spokane County as calculated by David Bezdicek of Washington State University.

The water quality of any surface or groundwater body to which reclaimed water is discharged is not expected to be adversely impacted. Reclaimed water discharged directly to water bodies such as the Spokane River would receive treatment  in accordance with Ecology standards and requirements prior to discharge.  Refer to Section 3.2 Water Resources for a detailed discussion of water quality issues in the Spokane area.

The use of treated effluent to recharge groundwater requires that the effluent be treated to drinking water and groundwater standards.  State standards allow groundwater recharge through surface percolation and direct injection.  The Reuse Standards include provisions requiring reclaimed water to be held underground a minimum of 12 months prior to being withdrawn for drinking water and a minimum horizontal distance separating the point of direct recharge and the point of withdrawal for drinking water.  These standards are intended to insure that aquifer recharge will not adversely impact groundwater quality.

No adverse impacts are expected as a result of using reclaimed water for wetland creation or enhancement.  Reclaimed water would be treated to Class A standards and created wetlands located in areas with potential interaction with potable water aquifers would be lined.  Beneficial impacts related to the restoration or enhancement of degraded wetlands could be anticipated as a result of using reclaimed water.  Reclaimed water would provide a reliable water supply in areas where natural flows have decreased as a result of development.

Impacts related to the use of reclaimed water for industrial uses could include a temperature increase in a facility's effluent, due to the fact that treatment plant effluent could be as much as 15 degrees warmer than groundwater.  This could require a facility to implement measures to cool the water to the facility's permitted temperature requirement prior to discharge.

Effluent application on poplar farms as part of an effluent end-use program would require approximately 3,600 acres by 2025, and approximately 4,500 acres in 2050, which includes land needed for buffers, harvesting requirements, and other property management functions.  The acreage required for the poplar farms could have impacts on land use in the Spokane area.  Impacts could include rezoning or redesignating land uses for selected tracts.  In addition, removing developable land from the tax rolls could adversely affect Spokane County's revenue stream.  A potential beneficial land use impact resulting from irrigation with reclaimed water could be an increase in the value of agricultural land that currently does not have a reliable water supply.

The effluent end use alternatives would all require a significant amount of energy due to extensive pumping requirements associated with transporting effluent.  Refer to Section 3.5, Energy and Natural Resources, for a description of energy and natural resource issues associated with wastewater treatment.

Reclaimed water treated to Class B standards or better does not carry an odor and has been treated and disinfected such that the number of total coliform organisms does not exceed 23 per 100 milliliters in any sample.  No impacts to air quality are anticipated as a result of effluent end use.  Effluent intended for reuse would be treated to Class A or Class B standards and does not carry an odor.  Refer to section 3.6, Air Quality, for a description of air quality issues associated with wastewater treatment. 

No long-term impacts to transportation are anticipated as a result of effluent (reclaimed water) end use activities.

4.1.2.3               Mitigation Measures

Mitigation for impacts associated with use of reclaimed water would include, the applicable measures in Ecology’s Water Reclamation and Reuse Standards (Ecology, 1997).  The appropriate standards for each type of end use would be applied.

Best management practices and standard noise and dust reduction techniques and erosion control measures would be used to minimize the impacts of construction.  No impacts to environmental health, plants and animals, air quality or transportation are expected to occur as a result of effluent end use activities, therefore, no mitigation is proposed.

4.1.3                   Biosolids Management

4.1.3.1               Affected Environment

Biosolids are the residual solids remaining after wastewater treatment.  Biosolids contain organic matter and plant nutrients.  This treatment by-product can make a good soil amendment and many communities, including Spokane, have successfully applied biosolids to farmland for decades.  Biosolids proposed for reuse in the Spokane Valley area would be treated to Class B standards or better. 

Relevant Local and State Standards and Guidelines.  Biosolids are regulated under Chapter 173-308 Biosolids Management of the Washington Administrative Code (WAC).  Chapter 173-308 WAC provides a definition of biosolids as used by Washington State and sets forth standards and guidelines for the treatment and use of this material.

The U.S. Environmental Protection Agency (EPA) established standards for biosolids disposal and use under 40 CFR 503 (the Part 503 rule) in 1993.  These guidelines are intended to protect public health and the environment from the adverse effects of certain pollutants that might be present in biosolids.  Three measures are used to determine if biosolids are of sufficient quality for use in various applications:  1) concentration of trace elements, 2) quantity of pathogens, and 3) vector (e.g., flies, rodents) attraction.

The alternatives for biosolids management include land application, composting, treatment at the City of Spokane facility, incineration, and privatized management.  Refer to Section 2.5.3 for a description of biosolids management alternatives.

4.1.3.2               Impacts

Construction. The composting alternative would experience construction-related impacts such as noise from construction equipment and vehicles, fugitive dust from excavation activities, and emissions from equipment and vehicle engines.  Construction-related impacts associated with the land application alternative would be minimal and would likely be limited to site preparation and possibly construction of access roads.  The co-incineration alternative would have no construction-related impacts because this alternative uses an existing regional incineration facility.  The treatment at City of Spokane Facility would require construction of a pump station and forcemain to transport sludge to the SAWTP.  This would involve significant construction impacts over a wide area.  Privatized management alternatives would have no construction-related impacts as the biosolids would be processed at an existing processing site.

Operation.  Because of the strict guidelines associated with the treatment and use of biosolids, no significant adverse impacts are expected as a result of use of this material. 

Composting of biosolids to produce Class A biosolids would require large areas of land and could pose siting problems.  Biosolids Alternative 3 would require approximately 20 acres of land.  This requirement could transfer this land from private ownership to public ownership and would remove it from the tax rolls.  Composting can generate significant odors which would impact site selection.

Biosolids would be treated to the strict guidelines that regulate biosolids treatment and use.  Therefore, no significant adverse impacts to water resources are expected.  Biosolids are required to be applied at agronomic rates to balance the uptake of nitrogen by crops with the potential for nitrate leaching to groundwater.  Adherence to these application rates and to requirements to buffer biosolids application areas from surface waters will minimize the impacts to receiving water bodies.  Required monitoring of soil and water concentrations will further protect water resources.

Environmental health concerns associated with biosolids could include exposure to microorganisms; metal concentrations in soil, water, and plants; and organic compounds.  Studies examining the potential health effects of pathogens in biosolids have shown no adverse health effects of land application of biosolids even in highly exposed individuals or in populations near biosolids recycling areas.  Large concentrations of trace metals such as copper, nickel, arsenic, mercury, lead, and cadmium have shown toxic effects on plants, animals, and humans.  The 503 regulations have strict "ceiling concentrations" on the amounts of these metals that are allowed in biosolids.  Biosolids that do not meet these requirements cannot be applied to land.

Biosolids would be sufficiently treated so that they do not produce significant amounts of odor.  Odors produced during treatment would be collected and treated prior to release to the atmosphere as described under Air Quality in section 3.6.  Some exhaust would be produced by heavy trucks used to transport biosolids from the plant to disposal areas.  Class B biosolids applied to agricultural lands may emit a musty organic or ammonia like odor when freshly applied.  The odor diminishes rapidly as the biosolids dry out.  Odor associated with biosolids application is very localized and dissipates quickly with distance.

Application of biosolids generally enhances the growth and vigor of plants.  Research has demonstrated that plants grown in biosolids amended soils pose no greater health risk than those without.  Animals can be adversely impacted by direct contact with biosolids or by alterations in vegetation.  Wildlife can be impacted by bioaccumulation of metals and trace organics; accumulation varies by species.  However, the application of biosolids does not appear to significantly affect wildlife populations.  In general, metal accumulation is low and not harmful to individuals or populations.  Under 503 regulations, biosolids cannot be applied on any site where they are likely to adversely affect endangered species.

Some energy may be saved as the result of land application of biosolids since the demand for chemical fertilizers will be reduced.  Production of chemical fertilizers requires large amounts of energy.  Energy will be expended in the transport of biosolids to the application or processing sites.  Offsite transport of biosolids by private contractors would require longer truck trips and consume more energy.

Impacts to transportation that result from biosolids management would generally be limited to heavy trucks entering and exiting the treatment plant site to transport biosolids to application or disposal sites.  Under Alternative 1, biosolids production is expected to increase; approximately three to four truck trips per day are anticipated for biosolids removal at an expanded SAWTP.  Alternatives 2 and 4 would add approximately three to four heavy truck trips per day to local streets for biosolids transport.  No significant adverse impacts to transportation are expected as a result of biosolids transport under Alternatives 1 through 4.  No additional truck traffic would be added to local streets as a result of Alternative 5; therefore, no impacts would occur.  Privatized management of the biosolids would generate longer truck trips with the biosolids.

Alternative 3, composting, would require trucking sludge to a composting site and then trucking the composted material to the point of distribution or use.  This would result in slightly increased truck traffic over Alternatives 2 and 4.

4.1.3.3               Mitigation Measures

Application or disposal of biosolids would comply with all local, state and federal regulations.  No biosolids application would occur on unauthorized properties.  All appropriate safeguards to protect human health and the environment would be followed.  These mitigation measures are expected to minimize the impacts associated with biosolids application.  In addition, the following mitigation measures could be implemented.

Biosolids will be monitored for concentrations of pathogens, trace metals, and organics compounds to ensure that the biosolids do not contain toxic levels of these materials.  In addition, soils will be monitored to gauge accumulations of trace metals and ground and surface water bodies will be monitored. 

Trucks transporting biosolids to use or disposal areas would follow all state and local regulations regarding transport of these materials.  Covering of truck beds and cleaning of excess materials from the outside of the truck bed prior to exit from the treatment plant site would insure that biosolids materials do not blow out of the truck and onto people, vehicles, or other property not intended for biosolids application.  Trucks used to transport biosolids would be maintained to minimize pollutants in exhaust fumes.  It is expected that loads would be covered to prevent materials from escaping the truck bed and introducing dust and debris into the air.

The relative significance of the addition of the three to four daily heavy truck trips to local roadways would be dependent upon the final site selection and existing traffic and road conditions in the area.  Mitigation measures could include traffic control devices such as traffic control improvements to local roadways (e.g., stop signs, turn lanes).

 


 

 


 

5.0                      References

Butkus, Steve, and Ken Merrill.  1999.  Spokane River Dissolved Metals Total Maximum Daily Load.  Publication No. 99-49-WQ.  Olympia, Washington:  Washington Department of Ecology.

California Energy Commission.  1999.  Efficiency Strategies, Variable-Frequency Drives.  Avail. online:  http://www.energy.ca.gov/water/tech/vfds.html.

City of Spokane.  2001a. Final Comprehensive Plan and Draft Environmental Impact Statement, an integrated GMA and SEPA Document, 2000-2020 (dated March 23, 2001).

City of Spokane.  2001b.  Spokane Municipal Code, Land Use.  City of Spokane, Planning Services Department.

City of Spokane.  2000.  Draft Comprehensive Plan and Draft Environmental Impact Statement, an integrated GMA and SEPA Document, 2000-2020.

City of Spokane.  1994.  Critical Areas Report.  City of Spokane Department of Planning Services.

City of Spokane.  1982.  Shoreline Master Program Supplement.  Use Regulations and Administrative Procedures. 

Ecology.  1999.  1999 Air Quality Trends in Washington.  Prepared by the Washington State Department of Ecology Air Quality Program.

Ecology.  2000.  Water Reclamation and Reuse: The Demonstration Projects.  Washington State Department of Ecology, Publication 00-10-062.

Ehrbar, Pat.  Avista Utilities.  Personal communications, telephone conversation with Deron Lozano, Adolfson Associates.  March, 2001.

Electric Power Research Institute.  1993.  Energy Efficiency in Wastewater Treatment.  TechCommentary.  March 1993: 3.

Johnston, L.  2001.  Personal telephone communication with Tina Loucks of Adolfson Associates, Inc., June 7, 2001.

Miller, Stan.  1996.  Unpublished report on hydraulic connectivity of the Spokane River.  Spokane Water Quality Management Program GIS.

Pelletier, Greg and Ken Merrill.  1998.  Cadmium, Lead, and Zinc in the Spokane River:  Recommendations for Total Maximum Daily Loads and Waste Load Allocations.  Publication No. 98-329.  Olympia, Washington:  Washington Department of Ecology.

Spokane County.  1974.  Shorelines Program.  Public works Department.  Building and Planning Division.  Spokane, Washington.

Spokane County.  1994.  Countywide Planning Policies for Spokane County.  Spokane County Growth Management Program, adopted December 22, 1994.

Spokane County.  1996.  Growth Management Essential Public Facilities Technical Committee Report.  Spokane, Washington.

Spokane County.  1996.  Critical Areas Ordinance for the Protection of Wetlands, Fish and Wildlife Habitats, and Geo-hayard Areas.  Spokane County Code.  Chapter 11.20.

Spokane County.  1998.  Zoning Code of Spokane County, Washington.  Public works Department.  Building Planning Division.  Spokane, Washington.

Spokane County.  2000a.  Spokane County Comprehensive Plan, Planning Commission Recommendation.

Spokane County.  2001a.  Construction Projects Status Report.  Spokane County Public Works, Web page edition, 2/2/2001.

Spokane County.  2001b.  Spokane Wastewater Facilities Plan.  Prepared by HDR Engineering.

Spokane County.  2001c.  Spokane County Wastewater Facilities Plan.  Basis of Planning Report.  Draft.  Prepared by HDR Engineering. 

Spokane County. 2001d.  Year 2000 Comprehensive Wastewater Management Plan (CWMP).

Spokane County Air Pollution Control Agency (SCAPCA).  2001a.  The SCAPCA Web site located at http://www.scapca.org on March 7, 2001.

Spokane County Air Pollution Control Agency (SCAPCA).  2001b.  Air Quality Index on the SCAPCA Web site located at http://www.scapca.org/cgi-bin/airquality.pl on March 7 and 14, 2001.

UMW Niugini Limited.  2001.  Index of New Equipment/data.  Avail online: http://www.umw.com.pg/newequip/data.

U.S. Department of Energy.  2000.  How to Select an Energy-Efficient Centrifugal Pumping System.  Located at http://www.eren.doe.gov/femp/procurement/pdfs/pump.pdf.

U.S. Fish and Wildlife Service (USFWS).  2001.  Written response to request for information on sensitive species. 

U.S. Geological Survey (USGS).  2001.  Water Resources Data for Washington.  Located at http://water.usgs.gov/wa/nwis.

Washington Department of Ecology.  1995.  Little Spokane River Watershed Initial Assessment.  May 1995.  Olympia, Washington.

Washington Department of Fish and Wildlife (WDFW).  2001.  Habitats and species Maps for Dartford, Greenacres, and Spokane Northeast, Northwest, Southeast, and Southwest Quadrangles.  Report dated March 27, 2001.

Washington Department of Health and Washington Department of Ecology.  1997.  Water Reclamation and Reuse Standards.  Olympia, Washington.

Water Environment Federation.  1997.  Energy Conservation in Wastewater Treatment Facilities.

 

 


 

6.0                      Distribution List

City of Spokane

Attn: Dale Arnold

909 E. Sprague

Spokane WA  99202

 

 

City of Spokane Library - Downtown

906 W. Main Avenue

Spokane WA  99201

 

 

District Corps of Engineers

Attn: Tim Erkel

P.O. Box 273

Chattaroy WA  99003

 

Environmental Protection Agency

Attn: Ben Cope

Water Division

1200 6th Avenue, MS OW-134

Seattle WA  98101

 

 

Inland Empire Paper

Attn: Rick Fink

3320 N. Argonne Rd

Spokane WA  99212

 

 

Kaiser Aluminum

Attn: Pat Blau

P.O. Box 15108

Spokane WA  99215

 

Liberty Lake Sewer & Water District No. 1

Attn: Lee Mellish

22510 E. Mission

Liberty Lake WA  99019

 

 

Soil Conservation Service, NRCS

Attn: Chris Miller

1908 N. Dale Lane

Spokane WA  99202

 

 

Spokane Conservation District

Attn: Walt Edelen

210 N. Havana

Spokane WA  99202

 

Spokane Co. Air Pollution Control Agency

Attn: Eric Skelton

1101 W. College Avenue

Spokane WA  99202

 

 

Spokane County Div. of Planning

Attn: Michael V. Needham, Director

1026 W. Broadway

Spokane WA  99260-0240

 

 

Spokane Co. Engineering & Roads Div.

Attn: Ross Kelley, P.E., County Engineer

1026 W. Broadway

Spokane WA  99260-0170

Spokane County Library - Argonne

4322 North Argonne

Spokane WA  99212

 

 

Spokane County Library

North Spokane

44 E. Hawthorne Road

Spokane WA  99218

 

 

Spokane County Library

Otis Orchards

22324 E. Wellesley

Otis Orchards WA  99027

 

Spokane County Library - Valley

12004 E. Main

Spokane WA  99206

 

 

Spokane County Water District #3

Attn: Ty Wick

Spokane Joint of Aquifer Board

P.O. Box 11187

Spokane WA  99211

 

Spokane Regional Health District

Attn: David Swink

1101 W. College Avenue

Spokane WA  99201

 

Spokane River Phosphorus Technical Advisory Committee

Attn: Tim Pelton/City of Spokane

4401 W. Aubrey L. White Parkway

Spokane WA  99205-3939

 

Spokane Tribe of Indians

Attn: Jim Seyler

P.O. Box 100

Wellpinit WA  99040

 

Spokane Valley Fire Department

10319 E. Sprague

Spokane WA  99206

 

Town of Millwood

Attn: Eva Combs, City Clerk

9103 E. Frederick

Spokane WA  99206

 

Washington State Dept. of Ecology

Environmental Review Section

PO Box 47703

Olympia WA  98504-7703

 

Washington State Dept. of Ecology

Attn: Heide Schieber/Doug Pineo

4601 N. Monroe Street, Suite 100

Spokane WA  99205-1295

Washington State Dept. of Health

Attn: Craig Riley

Drinking Water Division

1500 W. 4th Avenue, Ste. 305

Spokane WA  99204

 

Washington State Dept. of Agriculture

Attn: Tim Schultz

222 N. Havana

Spokane WA  99202

 

 

Washington State Dept. of Ecology

Attn: Ken Merrill

Water Quality Division

4601 N. Monroe, Suite 202

Spokane WA  99205

Washington State Dept. of Ecology

Attn: Cal Ferguson

Facility Planning Division

4601 N. Monroe, Suite 202

Spokane WA  99205

 

Washington State Dept. of Ecology

Attn: Jerry Anderson

Reuse Division

4601 N. Monroe, Suite 202

Spokane WA  99205

 

Washington State Dept. of Ecology

Attn: Tom Tebb

Shorelines and Wetlands Division

4601 N. Monroe, Suite 202

Spokane WA  99205

Washington State Dept. of Ecology

Attn: George Schlenger

Water Rights Division

4601 N. Monroe, Suite 202

Spokane WA  99205

 

Washington State Dept. of Ecology

Attn: Pat McGuire

Biosolids Division

4601 N. Monroe, Suite 202

Spokane WA  99205

 

Washington State Dept. of Fish & Wildlife

Attn: Jeff Lawlor

N. 8702 Division Street

Spokane WA  99218

 

Washington State Dept. of Natural Resources

Attn: Arnie Johnson

Northwest Region

P.O. Box 190

Colville WA  99114-0190

 

Spokane County Utilities

Attn:  Bruce Rawls, Director

Public Works Building

1026 W. Broadway

Spokane WA  99260

 

Spokane County Utilities

Attn:  Kevin Cooke

Public Works Building

1026 W. Broadway

Spokane WA  99260

 

Spokane County Utilities

Attn:  Stan Miller

Public Works Building

1026 W. Broadway

Spokane WA  99260

 

Washington Dept. of Ecology

Attn:  Carl Nuechterlein

Ecology Eastern Regional Office

Water Quality Division

N. 4601 Monroe, Suite 202

Spokane WA  99205

 

 

 

 

 

       


NOTICE OF AVAILABILITY

Avista Utilities (Electric & Gas Services)

1411 E. Mission

Spokane WA  99202

 

 

Historic Preservation Office

(City - County)

Attn: Teresa L. Brum, Director

808 West Spokane Falls Boulevard

Spokane WA  99201

 

Spokane County Community Development

721 N. Jefferson Street, Suite 200

Spokane WA  99260

 

Spokane Transit Authority

1230 W. Boone Avenue

Spokane WA  99260

 

 

City of Liberty Lake

Attn: Steve Peterson, Mayor

P.O. Box 370

Liberty Lake WA  99019

 

West Valley School District No. 363

District Administration Office

2805 N. Argonne

Spokane WA  99212

Washington Dept. of Transportation

Attn:  Jerry Lenzi, Regional Administrator

Eastern Region

2714 N. Mayfair Street

Spokane WA  99207

 

Inland Power & Light Company

320 East 2nd

Spokane WA  99202

 

City of Spokane Park Operations Dept.

810 N. Stone Street

Spokane WA  99203

 

Washington State Parks & Recreation Commission

Attn:  Marty Davis, Environ Planner

Eastern Region

2201 N. Duncan Drive

Wenatchee WA  98801

 

Spokane Valley Chamber of Commerce

8817 E. Mission Avenue

Spokane WA  99212

 

 

City of Spokane Fire Dept.

44 W. Riverside

Spokane WA  99201

 

Spokane Journal of Business

112 E. 1st Avenue

Spokane WA  99202

 

 

 

 

 

EDC - Economic Development Council

801 W. Riverside Avenue

Spokane WA  99201

 

 

 


 


 


 


 


 

 

                                    This site was last updated on:  Thursday November 08, 2001