INITIAL STUDY / PROPOSED NEGATIVE DECLARATION

CITY OF GALT WASTEWATER TREATMENT PLANT SUMMER SURFACE WATER DISCHARGE PROJECT

Prepared for:

CITY OF GALT

Prepared by:

July 2011

INITIAL STUDY / PROPOSED NEGATIVE DECLARATION CITY OF GALT WASTEWATER TREATMENT PLANT SUMMER SURFACE WATER DISCHARGE PROJECT

Prepared for:

CITY OF GALT PLANNING DEPARTMENT 495 Industrial Drive Galt, CA 95632

Prepared by:

9888 Kent Street Elk Grove, CA 95624 (916) 714-1801

July 2011

NEGATIVE DECLARATION

Project Title: City of Galt Wastewater Treatment Plant, Summer Surface Water Discharge Project

Lead Agency: City of Galt

Project Description

The Proposed Project consists of initiating discharge of WWTP effluent to Skunk Creek/Laguna Creek during the period of May 1 through October 31, annually, consistent with the provisions of the City’s NPDES permit. The City will continue to maximize irrigation of City-owned agricultural fields and will discontinue its lease to irrigate approximately 160 acres of adjacent agricultural fields owned by the Roman Catholic Bishop of Sacramento.

Project Location

City of Galt Wastewater Treatment Plant, 10059 Twin Cities Road, Galt, California 95632.

Project Proponent

City of Galt Public Works Department, 495 Industrial Drive, Galt, California 95632.

Negative Declaration

The City of Galt has found that the Proposed Project will have no significant effect on the environment.

Contact Person: Sandra Kiriu, Principal Planner City of Galt Planning Department 495 Industrial Drive Galt, California 95632 (209) 366-7230 Initial Study

The Initial Study documenting reasons to support findings of no significant effect on the environment is attached.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt MND-1 IS / Proposed ND TABLE OF CONTENTS

SECTION PAGE

1 INTRODUCTION ...... 1 1.1 Regulatory Guidance and Purpose of this Document ...... 1 1.2 Public Review of the Document ...... 2 1.3 Document Organization ...... 2 1.4 Summary of Findings ...... 3 2 PROJECT DESCRIPTION ...... 4 2.1 Project Location ...... 4 2.2 Purpose and Objectives of the Proposed Project ...... 4 2.3 Existing Facilities and Operations ...... 7 2.4 Proposed Project Operations and Maintenance Activities ...... 8 3 INITIAL STUDY / PROPOSED NEGATIVE DECLARATION ...... 10 3.1 Use of the Initial Study / Proposed Negative Declaration ...... 10 3.2 Aesthetics ...... 13 3.2.1 Setting...... 13 3.2.2 Discussion ...... 13 3.3 Agriculture and Forest Resources ...... 14 3.3.1 Setting...... 14 3.3.2 Discussion ...... 14 3.4 Air Quality ...... 15 3.4.1 Setting...... 15 3.4.2 Discussion ...... 15 3.5 Biological Resources ...... 16 3.5.1 Setting...... 16 3.5.2 Discussion ...... 20 3.6 Cultural Resources ...... 27 3.6.1 Setting...... 27 3.6.2 Discussion ...... 27 3.7 Geology, Soils, and Seismicity ...... 28 3.7.1 Setting...... 28 3.7.2 Discussion ...... 29

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc City of Galt i IS / Proposed ND TABLE OF CONTENTS

SECTION PAGE

3.8 Greenhouse Gases and Climate Change ...... 29 3.8.1 Setting...... 29 3.8.2 Greenhouse Gas Impact Discussion ...... 29 3.9 Hazards & Hazardous Materials ...... 30 3.9.1 Setting...... 30 3.9.2 Discussion ...... 30 3.10 Hydrology and Water Quality ...... 31 3.10.1 Setting...... 31 3.10.2 Discussion ...... 33 3.11 Stormwater Quality ...... 47 3.11.1 Setting...... 47 3.11.2 Discussion ...... 48 3.12 Land Use and Planning ...... 48 3.12.1 Setting...... 48 3.12.2 Discussion ...... 48 3.13 Mineral Resources...... 49 3.13.1 Setting...... 49 3.13.2 Discussion ...... 49 3.14 Noise ...... 49 3.14.1 Setting...... 50 3.14.2 Discussion ...... 50 3.15 Population and Housing ...... 50 3.15.1 Setting...... 50 3.15.2 Discussion ...... 50 3.16 Public Services ...... 51 3.16.1 Setting...... 51 3.16.2 Discussion ...... 51 3.17 Recreation ...... 51 3.17.1 Setting...... 52 3.17.2 Discussion ...... 52

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc City of Galt ii IS / Proposed ND TABLE OF CONTENTS

SECTION PAGE

3.18 Transportation/Traffic ...... 52 3.18.1 Setting...... 52 3.18.2 Discussion ...... 53 3.19 Utilities and Service Systems ...... 53 3.19.1 Setting...... 53 3.19.2 Discussion ...... 54 3.20 Mandatory Findings of Significance ...... 54 3.20.1 Discussion ...... 54 4 REFERENCES ...... 57 4.1 Printed References ...... 57 4.2 Personal Communications ...... 60 5 LIST OF PREPARERS ...... 60

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc City of Galt iii IS / Proposed ND

LIST OF TABLES

Table 1. Existing Monthly Average Irrigation Demand and Projected Effluent Discharge Rate at 3.0 MGD Capacity...... 9 Table 2. Flows (cfs) in Laguna Creek Upstream of the Discharge Point (Inflow), Lower Cosumnes River just Upstream of the Tidal Influence Area (Outflow), and the Corresponding Depth (ft) under Existing Conditions for Wetness Categories...... 22 Table 3. Project Flows (cfs) in Laguna Creek at the Discharge Point Including WWTP discharge (Inflow), Flows in the Lower Cosumnes River just Upstream of the Tidal Influence Area (Outflow), the Corresponding Depth (ft) and the Change in Depths (Diff) at the Tidal Influence Area under the Project Conditions for Wetness Categories...... 23 Table 4. EPA-Recommended Ambient Water Quality Criteria for Dissolved Oxygen...... 44

LIST OF FIGURES

Figure 1. Project Location Map...... 5 Figure 2. WWTP Facilities and Reclamation Irrigation Fields...... 6

APPENDICES

Appendix A Hydrologic Analysis of City of Galt Summer Surface Water Discharge Project

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc City of Galt iv IS / Proposed ND

1 INTRODUCTION

This document provides information to describe and evaluate the potential environmental effects of the City of Galt’s (City) proposed initiation of effluent discharges from the City’s Wastewater Treatment Plant (WWTP) to Skunk Creek during the months of May through October (Proposed Project). The City’s National Pollutant Discharge Elimination System (NPDES) permit and Waste Discharge Requirements (WDRs) for operating the WWTP, referred to as the NPDES permit for the purposes of this document, was renewed by the Central Valley Regional Water Quality Control Board (Regional Water Board) in September 2010 (NPDES No. CA0081434, WDRs Order No. R5-2010-0099). The renewed NPDES permit authorizes surface water discharge of treated effluent to Skunk Creek during the May 1 – October 31 period following implementation of effluent quality improvements at the WWTP. The City completed construction of treatment upgrades to the WWTP in January 2011, which included new tertiary filtration, ultraviolet light (UV) disinfection, and biosolids handling facilities. The WWTP upgrades are now operational, thereby achieving the permit-required effluent quality performance improvements, and thus facilitating implementation of the May through October surface water discharge project. Under the Proposed Project, the City would reduce the amount of effluent used in the summer months for irrigation of agricultural crops by eliminating irrigation on property not owned by the City. The discharge of effluent during the May through October period would be up to the maximum rate of 3.0 million gallons per day (MGD), which is the current permit and design capacity of the WWTP. However, the NPDES Permit still requires that the City continue reclamation activities via crop irrigation on property owned by the City during the summer months to the extent practicable. Agricultural irrigation demand varies on a monthly basis, depending on the weather and crop conditions. Thus, with the City’s continued reclamation operations on the City-owned fields, irrigation demand would reduce the average monthly rate of effluent discharge to Skunk Creek to a range of 1.6 to 2.5 MGD from May through October.

1.1 Regulatory Guidance and Purpose of this Document

This document has been prepared in accordance with the California Environmental Quality Act (CEQA), Public Resources Code 21000 et seq., and the State CEQA Guidelines, Title 14 California Code of Regulations (CCR) 15000 et seq. This Initial Study (IS) was prepared by the City (the Lead Agency) to determine if the Proposed Project could have significant impacts on the environment. In accordance with CEQA Guidelines 15064(a), an Environmental Impact Report (EIR) must be prepared if there is substantial evidence that a project may have significant impacts on the environment. If the Lead Agency determines that there is no substantial evidence for such impacts, or if the potential impacts can be reduced through project revisions or mitigation measures, a Negative Declaration (ND) or Mitigated Negative Declaration (MND) can be prepared (CEQA Guidelines 15070).

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 1 IS / Proposed ND

1.2 Public Review of the Document

The City, as the CEQA lead agency for the Proposed Project, has determined that an IS and proposed ND is the appropriate document for compliance with CEQA and the CEQA Guidelines. In accordance with Section 15073 of the CEQA Guidelines, this document will be circulated to local, state, and federal agencies and to interested organizations and individuals who may wish to review and comment on it. In reviewing this IS, affected public agencies and the interested public should focus on whether the document sufficiently identifies and analyzes the possible impacts on the environment.

A 30-day review and comment period for the IS/ND has been established in accordance with §15205(d) of the State CEQA Guidelines. This IS/ND is available for public review on the City’s website (www.ci.galt.ca.us/index.aspx?page=355) and during regular business hours at the Galt City Clerk’s office (380 Civic Drive, Galt, CA) and Marion O. Lawrence Public Library (1000 Caroline Avenue, Galt, CA). The 30-day public review period for the document is July 13, 2011 to August 11, 2011 at 5:30 p.m. Written comments on the IS/ND will be accepted during the comment period. If you wish to send written comments (including via E-mail), they must be submitted to the City by 5:30 p.m. on August 11, 2011. Postmarks will not be accepted if received after the close of the public review period.

Written, E-mail or faxed comments should be addressed to:

Sandra Kiriu, Principal Planner City of Galt Planning Department 495 Industrial Drive Galt, California 95632 Email: [email protected] Fax: 209-744-1642 Following the close of the public review period, the City Council will consider the IS/ND, and public comments received on the document, for potential adoption of the proposed ND.

1.3 Document Organization

This document is organized in the following manner:

ƒ Section 1, Introduction. This section provides an introduction and describes the purpose, scope, and organization of this document. ƒ Section 2, Project Description. This section describes the purpose and need of the Proposed Project, project objectives, and a description of the project’s characteristics. ƒ Section 3, Initial Study Discussion / CEQA Checklist. This chapter provides an environmental setting for the Proposed Project and analyzes the environmental impacts of the Proposed Project. Resource topics appear in the order that they appear in the CEQA Environmental Checklist. The environmental checklist is taken from Appendix G of the State CEQA Guidelines as supplemented by the City of Galt. Mitigation measures are

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 2 IS / Proposed ND

incorporated and discussed, where appropriate, to reduce “potentially significant” impacts to a “less-than-significant” impact level. Mandatory Findings of Significance also are presented in this section. ƒ Section 4, List of Preparers. This section identifies a list of people that assisted in the preparation of this document ƒ Section 5, References. This section identifies the references used in the preparation of this document.

1.4 Summary of Findings

Chapter 3 of this document contains the analysis and discussion of potential environmental impacts resulting from implementation of the Proposed Project. Based on the resources evaluated, it was determined that the Proposed Project would have no significant impact on the following resources:

ƒ Aesthetics, ƒ Agriculture and Forest Resources, ƒ Air Quality and Greenhouse Gases and Climate Change, ƒ Cultural Resources, ƒ Geology and Soils, ƒ Hazards and Hazardous Materials, ƒ Land Use and Planning, ƒ Mineral Resources, ƒ Noise, ƒ Population and Housing, ƒ Public Services, ƒ Recreation, ƒ Stormwater Quality, ƒ Traffic and Transportation, and ƒ Utilities and Service Systems. Impacts of the Proposed Project were determined to be less than significant for the following resources:

ƒ Biological Resources, and ƒ Hydrology and Water Quality. After completing the IS, the City determined that with project design and avoidance measures and best management practices, there are no potentially significant impacts to any resource area from the Proposed Project and, therefore, adoption of the proposed ND by the City Council is appropriate.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 3 IS / Proposed ND

2 PROJECT DESCRIPTION

2.1 Project Location

The Proposed Project would be located at the City’s existing WWTP, which is an approximately 298-acre incorporated property (for municipal purposes) about 4 miles north of the City center and surrounded by unincorporated Sacramento County. The WWTP is located at 10059 Twin Cities Road, which is about ½ mile north of Twin Cities Road, adjacent to the Union Pacific Railroad (UPRR) mainline tracks and 2,200 feet west of State Route 99 (Figure 1). The Assessor’s Parcel Number is 148-0010-053. The affected environment also includes the off-site surface receiving water stream of Skunk Creek into which the WWTP effluent is directly discharged, and the Laguna Creek and Lower Cosumnes River channels into which Skunk Creek flows immediately downstream of the WWTP.

2.2 Purpose and Objectives of the Proposed Project

The City currently discharges effluent to Skunk Creek from November 1 through April 30, but does not discharge to the creek from May 1 through October 31st, during which time all of the effluent is either land applied for irrigation of agricultural crops or stored in the reservoir. Agricultural irrigation occurs on approximately 174 acres of City-owned land and on approximately 160 acres of land leased from the Roman Catholic Bishop (RCB) of Sacramento (Figure 2). The WWTP currently has a design treatment and permit capacity of 3.0 MGD based on average dry weather flows (ADWF), which is defined in the permit as the average flow during the three traditionally driest months (e.g. July through September). The City (and WWTP service area) has a current population of approximately 24,000 people. Based on the City’s monitoring data for 2009 and 2010, the quantity of wastewater generated within the service area and conveyed to the WWTP averages about 2.35 MGD during the July through September period.

The WWTP is operated under the provisions of the NPDES permit issued to the City by the Central Valley Regional Water Board (NPDES No. CA0081434, WDRs Order No. R5-2010- 0099). All wastewater treatment plants in California are issued WDRs, and those that discharge to surface waters are also issued an NPDES permit, which set forth specific discharge requirements to ensure protection of public health and environmental health, and to meet state and federal water quality standards. Historically, the WWTP effluent discharge operations have been limited by the available land for reclamation irrigation operations, available effluent storage capacity, and by a former seasonal discharge prohibition contained in the City’s NPDES permit (i.e., 2004 renewal permit), which precluded surface water discharge from May 1 through October 31.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 4 IS / Proposed ND

Figure 1. Project Location Map.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 5 IS / Proposed ND

Figure 2. WWTP Facilities and Reclamation Irrigation Fields.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 6 IS / Proposed ND

In response to more restrictive regulatory provisions included in the City’s 2004 NPDES permit to meet applicable water quality standards during the winter surface water discharge period, the City conducted studies and implemented several improvements to the WWTP facilities. The City contacted agricultural landowners in the vicinity of the WWTP to evaluate the potential to alleviate regulatory and capacity constraints via increasing the size of the effluent reclamation irrigation operations. However, no landowners were amenable to selling or leasing properties for irrigation, and expansion beyond the nearby parcels was determined to be cost prohibitive. In addition, the RWQCB imposed a requirement on the 2004 NPDES permit to upgrade the WWTP to meet more stringent effluent quality standards.

The WWTP upgrades, completed in January 2011, included construction of new tertiary filters to provide improved suspended solids and turbidity removal, and conversion of the former chlorine-based wastewater disinfection system to an Ultraviolet (UV) light disinfection process. The City also constructed an effluent bypass pipeline in 2009 which provides for improved effluent discharge quality by allowing direct discharge of treated effluent, and avoiding passage of effluent through the effluent storage reservoir where treated effluent can comingle with reservoir water containing algae and suspended solids. Subsequently, the City’s NPDES permit was renewed in September 2010 (Order No. R5-2010-0099, NPDES No. CA0081434) and included regulatory changes that now allow for year-round surface water discharge.

Based on the new WWTP upgrades and resulting effluent quality improvements, the WWTP now fully meets the regulatory requirements of the NPDES permit which facilitates the ability to implement the May through October surface water discharge operations. The implementation of the annual May1 through October 31 surface water discharge to Skunk Creek is a Project as defined by CEQA, so it is evaluated in this initial study. The Proposed Project also fulfills other objectives of the City, including reducing the operational costs of the WWTP by discontinuing further lease payments and irrigation of the RCB property.

2.3 Existing Facilities and Operations

The existing WWTP consists of conventional extended aeration and activated sludge wastewater treatment processes consisting of headworks with screening and grit removal processes, two oxidation ditches, and two secondary clarifiers. Biosolids generated at the City’s WWTP are disposed of on City-owned agricultural lands surrounding the WWTP and/or removed by truck for land application off-site. The new tertiary filtration system is composed of engineered, high performance cloth-media filters, with small (10 micron) pore sizes that are mounted in stainless steel filter tanks. The new UV disinfection system consists of UV lamps submerged in open concrete channels, which provides for improved pathogen disinfection and virus inactivation compared to the former chlorine disinfection system. As filtered effluent travels through the channel, it is exposed to UV light, and any remaining pathogens are irradiated and rendered unable to reproduce. The UV dose applied in each channel can be adjusted based on the effluent flow rate. Effluent is conveyed from the UV channels to an effluent diversion box and an

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 7 IS / Proposed ND

isolation/diversion gate where effluent can be directly discharged to Skunk Creek or diverted to the existing effluent storage reservoir.

The WWTP provides a “tertiary” level of waste treatment, consistent with California Department of Public Health (DPH) regulations under Title 22, Title 22, Division 4, Chapter 3 of the California Code of Regulations (CCR, section 60301 et seq.). Wastewater effluent treated to a level consistent with Title 22 tertiary treatment regulations provides a high level of contaminant removal resulting in effluent that is acceptable for “unrestricted” reuse as defined by many forms of disposal activities including irrigation of food crops, landscape irrigation where public contact may occur (e.g., golf courses, parks), and discharge to surface water where human contact via contact recreation can occur.

As noted previously, the City currently maximizes agricultural irrigation on City-owned fields and City-leased RCB fields during the months of May through October. Beginning November 1 each year, effluent is discharged to Skunk Creek and continues until April 31, with very little to no agricultural irrigation occurring during these months.

2.4 Proposed Project Operations and Maintenance Activities

Under the Proposed Project, the City would also discharge tertiary treated effluent to Skunk Creek annually during May 1 through October 31, with no change to the current surface discharge operations during the period of November 1 through April 30. The City would discontinue the lease of RCB land for irrigation, but would continue irrigation on City-owned property to the extent practicable. The City could also agree to provide irrigation water to adjacent farmers if it does not become a cost burden to the City. Consequently, the maximum quantity of effluent discharged to Skunk Creek during the May through October period would reflect the amount of total wastewater inflow, up to the current WWTP capacity of 3.0 MGD, minus the quantity used for irrigation on City-owned land or discharged to the City’s effluent storage reservoir. The proposed discharge to Skunk Creek would be continuous, and discharge to the effluent storage reservoir would not be expected to be necessary. An upset in a WWTP treatment process unit, if it were deemed to result in effluent quality that could not meet the terms of the NPDES permit, is an example of a condition that might necessitate discharge to the effluent storage reservoir. Any such conditions would be expected to be temporary (i.e., no greater than 8 to 24 hours).

The rate of discharge to Skunk Creek that would occur during the May 1 through October 31 period under the Proposed Project was calculated as the difference between the 3.0 MGD WWTP capacity flow and the average monthly crop irrigation demands recorded for the City- owned fields during five years of available data (2003 and 2006 through 2009). The five years reflect a range of water year-types (i.e., according to the Department of Water Resources year- type classification) including two “dry” years, one “critically dry”, one “above normal”, and one “wet” year. Table 1 shows the existing irrigation water demand for City-owned fields and the projected surface water discharge rate of effluent under the Proposed Project.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 8 IS / Proposed ND

Table 1. Existing Monthly Average Irrigation Demand and Projected Effluent Discharge Rate at 3.0 MGD Capacity. Wastewater Irrigation Surface Discharge Month Influent MGD MGD MGD cfs May 3.00 1.1 1.9 3.0 June 3.00 1.4 1.6 2.5 July 3.00 1.4 1.6 2.5 August 3.00 1.2 1.8 2.8 September 3.00 1.0 2.0 3.2 October 3.00 0.5 2.5 3.9 Notes: cfs = cubic feet per second

Because no reclamation irrigation operations currently occur during the winter months of November through April, there would be no changes, relative to existing conditions, to the City’s surface water discharge operations during these months. No construction or other improvements to the WWTP facilities, nor any changes to the existing WWTP maintenance activities, would occur as part of the Proposed Project. Based on the operational assumptions for the Proposed Project, this IS does not assess the environmental effects of the Proposed Project during the November through April period because there would be no change in the discharge to Skunk Creek during this period of the year (i.e., the existing conditions and conditions with the Proposed Project would be identical). Because the City has never discharged effluent to surface water (i.e., Skunk Creek) during the May through October period, the focus of this Initial Study is the long-term operations-related environmental effects of effluent discharge to surface water during these months. Skunk Creek is dry during the May through October period when the proposed effluent discharges occur; Laguna Creek generally has streamflow present throughout the year as a result of supplemental water releases made upstream of the project area from the Sacramento Municipal Utility District’s Ranch Seco facility to support agricultural irrigation demands.

It should be noted that the City conducted CEQA compliance for the existing WWTP’s seasonal surface water discharges of up to the 3.0 MGD design capacity under separate CEQA documentation in 1990 for the last major facility expansion from 0.84 MGD to 3 MGD (Final EIR for the Wastewater Treatment Plant Expansion Project City of Galt, SCH# 89092511). An IS/MND was adopted in July 2009 for the recent tertiary filtration, UV disinfection, and biosolids dewatering facility upgrades (State Clearinghouse #2009062042).

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 9 IS / Proposed ND

3 INITIAL STUDY / PROPOSED NEGATIVE DECLARATION

This document was prepared, consistent with the California Environmental Quality Act (CEQA) pursuant to the Public Resources Code 21000 et seq. and the State CEQA Guidelines (Title 14, California Code of Regulations, 15000 et seq.).

3.1 Use of the Initial Study / Proposed Negative Declaration

The IS may be used by the CEQA “lead agency,” which is the City of Galt, to support the adoption of the proposed ND, pursuant to the State CEQA Guidelines Section 15070. The City’s current NPDES permit authorizes the surface water discharge consistent with the proposed project. Thus, the IS/ND documentation is not anticipated to be needed for any other public agency approval or action. The City Council must adopt the ND prior to taking action on the project. To adopt the ND, the City Council must find, on the basis of the whole record before it, that there is no substantial evidence that implementation of the project would result in significant effect on the environment, and that the ND reflects the City’s independent judgment and analysis of the potential environmental effects of undertaking the project. After the ND is adopted and all information is considered, the City Council may take action on the project. Using its independent judgment, the City Council may approve, make changes to, or reject the Proposed Project.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 10 IS / Proposed ND

ENVIRONMENTAL CHECKLIST

PROJECT INFORMATION City of Galt Wastewater Treatment Plant Summer Surface Water 1. Project Title: Discharge Project 2. Lead Agency Name and Address: Galt Planning Department, 495 Industrial Drive, Galt, CA 95632 3. Contact Person and Phone Number: Sandra Kiriu, (209) 366-7230 4. Project Location: 10059 Twin Cities Road, Galt, CA 5. Project Sponsor’s Name and Address: Galt Public Works Department, 495 Industrial Drive, Galt, CA 95632 Contact Person: Lisa Sanders, Senior Civil Engineer 6. General Plan Designation: Public/Quasi Public 7. Zoning: Public/Quasi Public 8. Description of Project: (Describe the whole action involved, including but not limited to later phases of the project, and any secondary, support, or off-site features necessary for its implementation. Attach additional sheets if necessary.) See Chapter 2, Project Description 9. Surrounding Land Uses and Setting: See Chapter 2, Project Description (Briefly describe the project’s surroundings) 10: Other public agencies whose approval is required: None (e.g., permits, financing approval, or participation agreement) ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED: The environmental factors checked below would be potentially affected by this project, involving at least one impact that is a “Potentially Significant Impact” as indicated by the checklist on the following pages.

Aesthetics Agriculture and Forest Resources Air Quality Biological Resources Cultural Resources Geology / Soils Greenhouse Gas Emissions Hazards & Hazardous Materials Hydrology / Water Quality Stormwater Quality Land Use / Planning Mineral Resources Noise Population / Housing Public Services Recreation Transportation / Traffic Utilities / Service Systems Mandatory Findings of Significance None With Mitigation

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 11 IS / Proposed ND

3.2 Aesthetics

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation

a) Have a substantial adverse effect on a scenic vista? b) Substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a state scenic highway?

c) Substantially degrade the existing visual character or quality of the site and its surroundings?

d) Create a new source of substantial light or glare which would adversely affect day or nighttime views in the area?

3.2.1 Setting

The City’s WWTP, including the project area, is located in a rural, agricultural area within Sacramento County. The 298-acre WWTP is an incorporated island for municipal purposes (WWTP), but is surrounded by unincorporated lands in the County. It is bounded by agricultural fields to the south and west, undeveloped habitat conservation land to the north (City of Galt and Wildlands, Inc.), and the Union Pacific Railroad to the east. State Highway 99 is located about 2,200 feet east of the WWTP site. Twin Cities Road is located approximately ½ mile south of the WWTP site and is proposed to be a scenic corridor in the Sacramento County General Plan. Views from the project site are dominated by flat agricultural land and scattered trees in the distance, as well as at least two cellular/radio towers. Union Pacific Railroad trains are visible from the WWTP.

3.2.2 Discussion

a-e) The Proposed Project would not involve any construction activity, and thus would not affect visual characteristics at the WWTP. The Proposed Project would result in additional streamflow in Skunk Creek, Laguna Creek, and the Lower Cosumnes River during the period of May through October each year. However, these channels are not generally visible from public lands, with the exception of the Twin Cities road bridge crossing over Laguna Creek, and additional streamflow would not adversely affect its visual characteristics. Therefore, the Proposed Project would not directly cause any adverse impact to aesthetics.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 13 IS / Proposed ND

3.3 Agriculture and Forest Resources

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance (Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non- agricultural use? b) Conflict with existing zoning for agricultural use, or a Williamson Act contract? c) Conflict with existing zoning for, or cause rezoning of, forest land (as defined in Public Resources Code section 12220(g)) or timberland (as defined in Public Resources Code section 4526)? d) Result in the loss of forest land or conversion of forest land to non-forest use? e) Involve other changes in the existing environment which, due to their location or nature, could result in conversion of Farmland, to non-agricultural use or conversion of forest land to non-forest use??

3.3.1 Setting

The existing WWTP area includes agricultural lands that surround the disturbed, ruderal area of the WWTP facilities. The City utilizes the onsite agricultural land it owns to reclaim biosolids and/or treated effluent. Prime or Unique Farmland, or Farmland of Statewide Importance (Farmland) exists within the WWTP area, but there are no Williamson Act contracts on the land (City of Galt 2008a). No forests are located within or adjacent to the WWTP area.

3.3.2 Discussion a-e) The Proposed Project would not involve any construction activity or proposed conversion of existing uses and thus would not affect agricultural resources. As a result of the RCB property not being leased by the City for agricultural purposes, the Proposed Project could result in less recycled water from the WWTP being used for agriculture. However, groundwater is readily available for continued agricultural production on the RCB property, if RCB chooses to continue agricultural operations in the future. In addition, the City is willing to continue to provide irrigation water to a willing farmer on this property is there is no significant cost burden to the City to do so. Therefore, the Proposed Project would not directly or indirectly result in conversion of farmlands into non-agricultural use. Thus, there would be no impact.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 14 IS / Proposed ND

3.4 Air Quality

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Conflict with or obstruct implementation of the applicable air quality plan? b) Violate any air quality standard or contribute substantially to an existing or projected air quality violation? c) Result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard (including releasing emissions which exceed quantitative thresholds for ozone precursors)? d) Expose sensitive receptors to substantial pollutant concentrations? e) Create objectionable odors affecting a substantial number of people?

3.4.1 Setting

The project area lies within Sacramento County and the Sacramento Valley Air Basin (Basin). Air quality within the Sacramento County portion of the Basin is regulated by the U.S. Environmental Protection Agency (EPA), the California Air Resources Board (ARB), and the Sacramento Metropolitan Air Quality Management District (SMAQMD). The EPA and ARB have set ambient air quality standards for certain air pollutants to protect the public health and welfare. The EPA has established National Ambient Air Quality Standards (NAAQS) for the following criteria pollutants: carbon monoxide (CO), ozone (O3), sulfur dioxide (SO2), nitrogen dioxide (NO2), inhalable particulate matter (PM10), fine particulate matter (PM2.5), and lead (Pb). ARB has set California Ambient Air Quality Standards (CAAQS) that are the same or are more stringent than the corresponding federal standards. The CAAQS also includes standards for sulfates, hydrogen sulfide, and visibility.

If an area has not achieved the NAAQS or CAAQS for any criteria pollutant, the EPA and ARB classifies it as a nonattainment area for the respective criteria pollutant. A nonattainment area is required to have an air quality plan to attain and maintain the required standards. Sacramento County is designated as a federal and state nonattainment area for ozone, PM10, and PM2.5 and as an attainment area for all other pollutants.

3.4.2 Discussion a-e) The Proposed Project would not involve any construction activity or change in WWTP operations that would result in any changes in air emissions or odors associated with the facility. Therefore, there would be no impact.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 15 IS / Proposed ND

3.5 Biological Resources

Less than Potentially Less than Significant Significant Significant No Impact Would the project… with Impact Impact Mitigation a) Have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service? b) Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations or by the California Department of Fish and Game or US Fish and Wildlife Service? c) Have a substantial adverse effect on federally protected wetlands as defined by Section 404 of the Clean Water Act (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means? d) Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites? e) Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance? f) Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan?

3.5.1 Setting

The Proposed Project is located in an agricultural region of Sacramento County at approximately 30 feet above mean sea level. The Proposed Project is bordered by agricultural fields on the east, south, and southwest. Land west of the Proposed Project’s area is undeveloped. Land north of the site is also undeveloped and will remain so because of habitat conservation mitigation easements on the land (City of Galt and Wildlands, Inc.). Water bodies potentially affected by the Proposed Project include a remnant portion of Skunk Creek, which receives discharge from the WWTP and conveys it approximately 0.6 miles, at which point it is tributary to Laguna Creek. Discharges flow down Laguna Creek, which is tributary to the Lower Cosumnes River, which is tributary to the Mokelumne River and the Sacramento-San Joaquin Delta (Delta). An 18-acre effluent storage reservoir exists on the plant site, and is part of the WWTP infrastructure. The reservoir is used to store treated effluent, which can then be sent from the reservoir to adjacent fields for land disposal, or discharged to Skunk Creek. The WWTP also has the capability to discharge treated effluent to the creek immediately following UV disinfection, thereby bypassing the effluent storage reservoir. Operations and maintenance activities at the

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 16 IS / Proposed ND

reservoir are implemented on an as-needed basis and include drawing down the reservoir to remove sediment and removal of vegetation from the reservoir and surrounding berms.

For the purposes of this document, a special-status wildlife species is defined as any species that is granted status by a federal, state, or local agency. Federally listed species are those granted status by federal agencies as threatened (FT), endangered (FE), proposed threatened or endangered (FPT, FPE), candidate (FC), or listed species proposed for delisting (FPD). State of California listed wildlife species are defined as those species granted status as state threatened (ST), state endangered (SE), California Fully Protected species (CFP), and species of special concern (CSC).

Existing documents pertinent to special-status plant and wildlife species in the vicinity of the Proposed Project were compiled, reviewed, and analyzed. This included a review of the U.S. Fish and Wildlife Service (USFWS) Species List (USFWS 2011), California Department of Fish and Game (CDFG) California Natural Diversity Database (CNDDB) (CDFG 2009), City of Galt General Plan Existing Conditions Report for the 2008 General Plan (City of Galt 2005), and the City of Galt General Plan Draft Environmental Impact Report (EIR) (City of Galt 2008a). Relevant technical information from these documents is incorporated by reference herein.

As noted in Section 2.4, only the WWTP operations would change to facilitate effluent discharge during the months of May through October, and no construction activities would occur under the Proposed Project. Consequently, the Proposed Project would have no direct adverse effects on plant or terrestrial wildlife species, nor would it significantly alter their habitat. Because the Proposed Project adds water that meets water quality standards to the receiving water bodies, it augments water supplies for riparian habitats and wildlife and thus is not anticipated to result in any adverse indirect effects on plant or terrestrial wildlife species. Consequently, no further assessment of effects to plant or terrestrial wildlife species is warranted.

No special-status resident fish species occur in Skunk Creek or Laguna Creek and there are no documented occurrences of special-status anadromous fishes with natal runs in either of these water bodies. However, the Cosumnes River and its terminal drainage, the Mokelumne River, support annual runs of Central Valley Evolutionarily Significant Unit (ESU) fall-run Chinook salmon (Oncorhynchus tshawytscha), a federal species of concern. In addition, the Lower Cosumnes-Lower Mokelumne Hydrologic Unit, which contains the tributaries Laguna Creek and Skunk Creek, is identified as Essential Fish Habitat (EFH) for Chinook salmon. In addition, the Mokelumne River supports an annual run of Central Valley ESU steelhead (O. mykiss). Central Valley ESU steelhead were listed as threatened under the federal ESA on March 19, 1998 (63 FR Part 13347); no State designation has been made. Critical habitat was designated for the Central Valley Distinct Population Segment (DPS) steelhead on September 2, 2005 (70 FR 52488) and includes the lower Mokelumne River downstream of Camanche Dam, but does not include the Cosumnes River or any of its tributaries, including Laguna Creek and Skunk Creek.

Fall-run Chinook salmon may make opportunistic use of Laguna Creek in years of favorable hydrologic conditions in Laguna Creek, relative to the Cosumnes River and, consequently, may

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 17 IS / Proposed ND

occur in the vicinity of the project area. However, based on historical records and Laguna Creek habitat, such opportunistic use of Laguna Creek is both uncommon and expected to be unsuccessful (with regard to spawning and reproduction) when it does occur. Due to a lack of suitable habitat (e.g., substrate, appropriate water velocities and depths) and other environmental factors (e.g., temperature), Chinook salmon that stray into Laguna Creek would likely die without spawning, or their eggs would perish following spawning due to unfavorable creek substrate egg incubation conditions.

Migration Behavior of Fall-run Chinook Salmon. Anadromous salmonids, including fall-run Chinook salmon, have a strong tendency to return to their natal stream to spawn as adults, a concept referred to as “homing.” The ability of these fish to return to their natal streams after ocean residency is primarily based on their ability to detect distinct olfactory cues (i.e., odors) associated with their natal streams. Research has demonstrated that juvenile salmonids “learn” the chemical characteristics of their natal stream through a process commonly referred to as “olfactory imprinting” (Hasler et al. 1978), in which the affinity for their natal water becomes established as they sequentially memorize the odors associated with the waters of their natal stream during early rearing and at key points (e.g., confluences of rivers) in their downstream migrations (Dittman et al. 1996; Schroeder et al. 2001). The homing ability of anadromous salmonids is thought to be advantageous from a life history perspective in that the likelihood of successful spawning in their natal streams is generally high, which is self-evident, based on the fact that habitat conditions were previously suitable for their own existence (Quinn 2005).

However, despite their affinity for their natal stream, a small portion of most anadromous salmonid populations have a tendency to stray into non-natal waters during their return migrations, as evidenced by anecdotal observations of fall-run Chinook salmon in Laguna Creek in 2003. Quinn (2005) identified three primary factors that may influence the relative frequency of straying: (1) the stability of the natal river system, (2) the extent of a species’ specialization in terms of freshwater habitat use, and (3) the variation in a given population’s age at maturity and extent of iteroparity (repeat spawning). Given the high degree of variability in the Cosumnes River’s hydrology, the ephemeral nature of much of the lower channel, and the environmental factors (e.g., rainfall, groundwater level) affecting the seasonal hydrologic connection from its lower tidally influenced reach to the upper reaches with suitable spawning habitat for fall-run Chinook salmon, the stability of the river discussed by Quinn (2005) is highly relevant to the likelihood of straying. He hypothesizes that straying may be a more important factor in streams that exhibit higher inter-annual variability (e.g., flashy coastal streams), where higher rates of straying would provide an ecological advantage during years in which conditions in the natal stream are unsuitable for spawning, egg incubation, and early rearing. Consequently, an increased potential for straying would be expected by fall-run Chinook salmon holding in the Lower Cosumnes River during years in which dry fall conditions prevent access to the upper natal reaches during the peak spawning period (i.e., November), regardless of the water source.

The relative proportion of a population that is likely to stray can be variable, but is generally small. In a 3-year study of 1.2 million tagged Chinook salmon smolts, Quinn and Fresh (1984)

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 18 IS / Proposed ND

observed that, of the approximately 41,000 adults that were recovered, only 1.4% strayed from their natal stream. These researchers also noted that the proportion of fish straying increased with age-class. Other studies have observed substantially higher rates of straying in hatchery fish. Studies of Columbia River hatchery fish observed levels of straying ranging from 5-19%, with an average of 11% (Quinn et al. 1991; Pascual and Quinn 1994). In California, Mesick (2010) reported straying rates of up to 58% of Merced River Hatchery fall-run Chinook salmon from 1979 through 2007. The strays were recovered in the Sacramento River system when San Joaquin River flows were low or Delta exports at the State and federal pumping facilities were elevated during the October and November period. When San Joaquin River October-November flows were low (i.e., below 3,300 cfs as a period average, as measured at Vernalis), stray rates ranged from approximately 5-58%, but ranged from 0-5% when Vernalis flows exceeded 3,300 cfs as a period average.

Cosumnes River Fall-run Chinook Salmon. Straying of Chinook salmon likely plays an important role in the Cosumnes River. The Cosumnes River historically supported moderate size runs of fall-run Chinook salmon, with escapement ranging from several hundred to approximately 4,400 fish between 1953 and 1973 (CDFG GrandTab 2011). In recent decades, however, annual runs have ranged from 0 to approximately 1,350 fish, but have typically been less than 200 (CDFG GrandTab 2011). Declines in the Cosumnes River populations are apparently due to the altered and unstable hydrology of the system during the critical salmon migration period coupled with a short supply of suitable spawning and rearing habitat located in the upper reaches of the river. Fish from the Mokelumne River Hatchery have been planted historically in the Cosumnes River and strays from the Mokelumne River (as identified by the presence of clipped adipose fins and coded wire tags [CWT]) are found annually in the Cosumnes River (Kennedy pers. comm.). The degree of natural production that occurs in the Cosumnes River is unknown; however, based on the number of stray Mokelumne River hatchery fish observed in the river and the fact that no observable production occurs in some years (i.e., when hydraulic connection occurs after the spawning period), it is likely that the runs of Chinook salmon in the Cosumnes River are composed of a combination of hatchery-derived strays from the Mokelumne River that make opportunistic use of the Cosumnes River in years of favorable conditions and fish originating from the Cosumnes River. The relative proportion of fish originating from each source is likely variable on an inter-annual basis; however, it is believed that Mokelumne River hatchery fish compose approximately 25% of the Cosumnes River population on average (Kennedy pers. comm.).

Given the degree of straying that naturally occurs in wild Chinook salmon populations and the elevated potential for straying based on the unique and unstable characteristics of the Cosumnes River’s hydrology and the substantial proportion of the run composed of stray Mokelumne River hatchery-derived fish, straying is likely to occur on a relatively elevated basis in the Cosumnes River in most years. In years in which the Cosumnes River connects to suitable upstream spawning reaches during the primary (i.e., October-December) spawning period, a portion of fall-run Chinook salmon may stray into non-natal tributaries (e.g., Laguna Creek). Based on available information, straying of Cosumnes River fall-run Chinook salmon into Laguna Creek

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 19 IS / Proposed ND

occurs infrequently, and conditions within Laguna Creek are not conducive to successful reproduction of fall-run Chinook salmon.

3.5.2 Discussion a,d) The Proposed Project would not involve any construction activity, and thus there is no potential to cause direct adverse construction-related effects on special status species, sensitive communities, or their habitats (through habitat modifications) identified in agency’s plans, policies, or regulations.

The Proposed Project would result in the discharge of treated effluent into Skunk Creek during the period May through October, annually. This would create surface flows in the remnant portion of Skunk Creek, which meet applicable water quality standards, during months when effluent has not historically been discharged to surface water. In addition, this summer discharge will add additional flow to the existing May–October flows that exist in Laguna Creek and the lower reach of the Cosumnes River (downstream of its confluence with Laguna Creek). Consequently, the Proposed Project would affect the May through October hydrology of the water body reaches identified above by adding additional flow to these channels during this period of the year, relative to existing conditions (see Appendix A). The addition of project flow to these water bodies, which meets applicable water quality standards, would not interfere with the movement of any avian or terrestrial wildlife species, would not adversely affect any area avian or terrestrial wildlife populations, and would not in any way impede the use of native wildlife nursery sites. Moreover, the addition of project flow to these water bodies would not adversely affect any area amphibian populations, and would have either no effect or beneficial effects on the riparian corridor along the affected water body reaches.

Because the Proposed Project’s addition of flows to the remnant reach of Skunk Creek and Laguna Creek will comply with applicable water quality standards (see Section 3.10, Hydrology and Water Quality for additional details), as required by the City’s NPDES permit for this WWTP, such additional flows would not result in any substantial adverse water quality related effects to the aquatic biological resources within the affected water body reaches. In fact, the project discharges will create both aquatic habitat and aquatic communities of benthic macroinvertebrates and fish within the Skunk Creek channel where they have historically not existed due to zero surface flow during the May through October period. The additional flow added to Laguna Creek (downstream of its confluence with Skunk Creek) and the Cosumnes River (downstream of its confluence with Laguna Creek) will not adversely affect water quality within these water bodies by magnitude and frequency that would adversely affect populations or communities of aquatic species using these water bodies, nor will it substantially or adversely affect aquatic habitat within the affected reaches.

To complete this assessment, the hydrologic effect of the Proposed Project on the approximately 1.5 mile reach of the Lower Cosumnes River between its confluence with Laguna Creek and the upper extent of tidewater within the Lower Cosumnes River channel required analysis to specifically assess whether the Proposed Project would interfere substantially with the migratory movement of fall-run Chinook salmon that utilize the Cosumnes River.

Fall-run Chinook salmon is the only anadromous salmonid that has a natal run using the Cosumnes River on an annual basis. Therefore, this assessment was focused on determining whether the Proposed Project would create flow conditions within Laguna Creek and the lower reach of the

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 20 IS / Proposed ND

Cosumnes River that would substantially increase the potential for fall-run Chinook salmon to stray into Laguna Creek, thereby potentially preventing them from reaching their true spawning grounds in the upper reaches of the Cosumnes River.

Upon their return from the ocean, the primary cues that adult fall-run Chinook salmon use to find their natal river for spawning are: 1) olfactory cues (i.e., the smell of their natal river, where they were spawned and thus originate from), and 2) flow and flow rate (referred to as rheotaxis). Olfactory cues are by far the dominant cues that salmonids use to find and migrate up their natal river. Rheotaxis comes into play, generally to a lesser degree than that of the olfactory cues, at tributary confluences, where channels are braided (i.e., water flows through multiple channels vs. a single channel), at dams with fish ladders, and similar situations. In such cases, the migrating salmon use rheotaxis to find a pathway to upstream spawning grounds and to avoid channels that are too shallow for passage. For example, if the channel splits in their natal river, and most of the flow is going through one channel with less flow through the other, most migrating fall-run Chinook salmon will select the channel with greater flow. This behavior reduces the likelihood that adult migrating salmon get stranded in shallow, impassible riffles while attempting to reach upstream spawning grounds.

The issue here with regards to the Proposed Project and Cosumnes River fall-run Chinook salmon is whether the additional WWTP discharges during the May through October period will create a surface flow hydraulic condition within Laguna Creek and the Lower Cosumnes River (between its confluence with Laguna Creek and the upper extent of tidal influence) such that fall-run Chinook salmon will be attracted up Laguna Creek in their efforts to spawn, rather than staying within the Cosumnes River until its surface flows allow passage to upstream spawning habitats. This is important because successful reproduction of fall-run Chinook salmon occurs when these fish reach upstream spawning habitats within the Cosumnes River (their natal river) which occurs in the mainstem of the Cosumnes River upstream of Highway 16, which is approximately 27 miles upstream of the Laguna Creek confluence. Fall-run Chinook salmon, should they enter Laguna Creek, are not expected to be able to successfully reproduce within this creek due to lack of suitable habitat within the creek for successful egg incubation and early life stage rearing. Hence, adult salmon that immigrate into Laguna Creek may fail to reproduce, unless they find their way back out and up the Cosumnes River to spawning habitats where they can reproduce successfully.

To asses this potential effect of the Proposed Project on fall-run Chinook salmon, hydrologic conditions were assessed with the U.S. Army Corps of Engineers Hydrologic Engineering Centers River Analysis System (HEC-RAS) model which was developed and used to estimate: 1) whether surface flow continuity (i.e., continuous flows) exists throughout Laguna Creek and the lower reach of the Cosumnes River from its confluence with Laguna Creek to tidewater; and 2) the minimum depth of flows within the Cosumnes River channel during the May through October period, under both existing and with-project conditions. A description of the model, its development and a summary of its output is provided in Appendix A.

Flows in Laguna Creek upstream of the WWTP discharge location (referred to in Appendix A as “inflow”), in the lower reach of the Cosumnes River just upstream of tidal influences (referred to in Appendix A as “outflow”), and the corresponding depth in feet at the outflow location under existing conditions is provided in Appendix A, Table 4. For the readers convenience, this same information is also presented in Table 2. The “outflow” depth is believed to be the minimum depth

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 21 IS / Proposed ND

within the Cosumnes River reach extending from its confluence with Laguna Creek to the area of tidal influence, and is located just upstream of the tidal area. As shown in Table 2, surface flow continuity throughout Laguna Creek and the Lower Cosumnes River to the area of tidal influence typically occurs in wet years, except during July, when surface flow continuity does not exist in the Lower Cosumnes River between its confluence with Laguna Creek and the area of tidal influence. Surface flow continuity in this lower reach of the Lower Cosumnes River generally does not occur June through August in average and dry wetness categories (Table 2). Although modeling showed surface flow continuity throughout the reach of the Lower Cosumnes River between its confluence with Laguna Creek and the area of tidal influence in September and October of all water year types for the period of available data for Rancho Seco release flows (i.e., 2002–2009), minimum water depths within the Lower Cosumnes River channel just upstream of the tidal water area was estimated to be less than 6 inches in September during years associated with the average and dry wetness categories, and estimated to be 10–11 inches deep here in wet years. Water depths less than 6 inches would be expected to prevent upstream migration of adult fall-run Chinook salmon holding at the tidal water area in September. In October under existing conditions, the modeling estimated that the minimum water depth within the reach of the Lower Cosumnes River between its confluence with Laguna Creek and the area of tidal influence to be greater than 1 ft during all water year types evaluated (Table 2).

Table 2. Flows (cfs) in Laguna Creek Upstream of the Discharge Point (Inflow), Lower Cosumnes River just Upstream of the Tidal Influence Area (Outflow), and the Corresponding Depth (ft) under Existing Conditions for Wetness Categories. Wet Average Dry Month Inflow Outflow Depth Inflow Outflow Depth Inflow Outflow Depth cfs ft cfs ft cfs ft May 14.07 10.70 1.26 9.06 5.78 0.92 6.77 2.60 0.62 June 7.30 3.85 0.76 3.74 0.00 0.00 4.63 0.34 0.20 July 2.23 0.00 0.00 2.60 0.00 0.00 1.05 0.00 0.00 Aug 8.73 3.92 0.77 5.26 0.00 0.00 3.57 0.00 0.00 Sep 9.82 5.18 0.88 7.01 1.32 0.45 6.08 0.53 0.27 Oct 13.51 7.46 1.07 12.98 6.95 1.04 13.37 7.32 1.06

Based on the above, adult Chinook salmon could migrate up into Laguna Creek during October, under existing conditions in all years assessed (2002-2009) because the modeling estimates that sufficient depth and surface flow continuity exists to facilitate such passage. This surface flow continuity in October under existing conditions was further confirmed via review of available aerial photographs, which showed surface flow continuity in this reach of the Lower Cosumnes River during this timeframe in 2002 and 2010. The 2002 and 2010 water year-types were “dry” and “below normal,” respectively, which supports the conclusion that surface flow continuity estimated in the model is reasonable for all other water year categories. Nevertheless, interviews with WWTP operators revealed that adult salmon strayed into Laguna Creek only 2 times (i.e., November 2003 and in the fall of 2006 or 2007 [specific date not recorded]) in the past decade (Dahlberg, pers. comm.). This indicates that despite their physical ability to migrate from the tidal water area up to

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 22 IS / Proposed ND

the WWTP outfall, adult fall-run Chinook salmon do so rarely. This is believed to be the case because the water flowing down Laguna Creek and wetting the Lower Cosumnes River channel is primarily American River water diverted into the Folsom South Canal, delivered to Rancho Seco, and then conveyed down Laguna Creek. Not being Cosumnes River water, there is no olfactory cue for Cosumnes River fall-run Chinook salmon holding at tide water, and thus most of these salmon choose to continue holding in the tidally influenced area waiting for the Lower Cosumnes River to flow following sufficient rains rather than stray into non-natal waters.

The same assessment using the HEC-RAS model was conducted for the Project conditions(Appendix A, Table 6). For the readers convenience, this same information is also presented in Table 3 (below).The Proposed Project discharges would create more frequent surface flow continuity in the Lower Cosumnes River during the summer months (i.e., in July of wet years, and in July and August of average and dry years), relative to existing conditions. In September of average years, minimum water depths that were slightly less than 6 inches (i.e., 5.4 inches) under existing conditions are increased incrementally to an estimated 9.2 inches (i.e., an estimated maximum expected increase in minimum depth of approximately 4-5 inches). In October, minimum water depths within the Lower Cosumnes River between its confluence with Laguna Creek and the area of tidal influence would increase about 2-3 inches, relative to existing conditions, resulting in minimum depths of about 1.25 ft in all wetness categories assessed (Table 3). It should be noted that fall-run Chinook salmon do not begin to congregate and hold at the upper boundary of the tidally influenced area within the Lower Cosumnes River channel until September (in some years) and typically not until October. The primary spawning season is mid- October through December, with peak spawning in November when flows are sufficient to reach upstream spawning habitats. Thus, the surface flow continuity differences caused by the Proposed Project during the May through August period of the year would have no effect on spawning success of Cosumnes River fall-run Chinook salmon because they are not present during these months.

Table 3. Project Flows (cfs) in Laguna Creek at the Discharge Point Including WWTP discharge (Inflow), Flows in the Lower Cosumnes River just Upstream of the Tidal Influence Area (Outflow), the Corresponding Depth (ft) and the Change in Depths (Diff) at the Tidal Influence Area under the Project Conditions for Wetness Categories. Wet Average Dry Month Inflow Outflow Depth Diff Inflow Outflow Depth Diff Inflow Outflow Depth Diff cfs ft cfs ft cfs ft May 17.08 13.65 1.38 0.12 12.07 8.73 1.14 0.22 9.78 5.33 0.89 0.27 June 9.82 6.26 0.96 0.20 6.26 1.87 0.53 0.53 7.15 2.55 0.60 0.40 July 4.72 0.65 0.29 0.29 5.09 0.68 0.29 0.29 3.53 0.00 0.00 0.00 Aug 11.52 6.58 1.01 0.24 8.06 1.86 0.53 0.53 6.37 0.55 0.27 0.27 Sep 12.99 8.23 1.11 0.23 10.18 3.93 0.77 0.32 9.25 3.07 0.68 0.41 Oct 17.37 11.06 1.27 0.20 16.84 10.55 1.25 0.21 17.23 10.93 1.26 0.20

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 23 IS / Proposed ND

The City currently discharges to surface waters during the November 1 through April 30 period, annually. Hence, come November, surface flow continuity differences between existing conditions and Project conditions rapidly diminish, resulting in negligible difference between existing and Project surface flow continuity conditions during the latter November through April period. Based on these facts, the period of concern regarding effects of the Proposed Project on spawning success of Cosumnes River fall-run Chinook salmon is September through mid November. The remainder of this fall-run Chinook salmon assessment will focus on this period.

No other runs of Chinook salmon use the Cosumnes or Mokelumne rivers and thus no other runs of salmon require assessment herein. Likewise, a natal run of steelhead does not occur in the Cosumnes River, but one does occur in the Mokelumne River. Nevertheless, no steelhead spawning has ever been documented in the Cosumnes River and the Mokelumne River steelhead spawning typically occurs October through March. During the October through March period, the Lower Cosumnes River has surface flow continuity from its confluence with Laguna Creek to tide water under existing conditions. Therefore, the Proposed Project would not cause surface flow continuity during this period of the year when it would not otherwise occur without the Project; rather, as shown in Table 3, flows would simply be slightly greater in the Lower Cosumnes River and Laguna Creek, relative to existing conditions. Hence, the Proposed Project would have no effect on the opportunistic use of the Cosumnes River by Mokelumne River steelhead that may stray into and utilize the Cosumnes River under suitable hydrologic conditions. Because the Mokelumne River flows typically exceed those of the Lower Cosumnes River in October and November, straying of steelhead from the Mokelumne River (their natal river) to the lower flow Cosumnes River during these months is expected to occur extremely infrequently, if it occurs at all. Consequently, the Proposed Project would have no effect on the Mokelumne River steelhead population.

In most years, the earliest arriving Cosumnes River fall-run Chinook salmon must hold in the lowest reach of the river channel where tidal influences create a constant channel inundation (i.e., area of tidal influence). These fish have used their olfactory cues to find the Cosumnes River, but typically find under existing conditions that the river is not yet flowing and thus they cannot migrate to upstream spawning habitats. These adult salmon hold within the area of tidal influence, waiting until fall rains cause the river to flow and connect to tidal water. Once surface flow continuity becomes established throughout the Lower Cosumnes River, the waiting adult salmon quickly migrate to upstream spawning habitats within the Cosumnes River and spawn.

Available information (i.e., Appendix A modeling output and conversations with WWTP operators and Cosumnes River fisheries experts) indicates that despite sufficient surface flow continuity for salmon to have migrated up Laguna Creek to the WWTP outfall in most, if not all years of the 2002-2009 record, they did not do so. The one specific confirmed date by the current plant operators of adult salmon up near the WWTP outfall in the past 8 years was November 18, 2003 (Dahlberg, pers. comm., 2011). Surface flow continuity throughout the entire Lower Cosumnes River was not likely occurring at this time because Michigan Bar flows were <50 cfs in November and less about 10 cfs during October. Historically, flows at Michigan Bar need to be approximately 70 cfs or greater for surface flow continuity to occur throughout the entire river, from its headwater to the area of tidal influence. The salmon observed near the WWTP outfall in 2003 (about 20 fish) simply strayed into Laguna Creek at this time. No observations of salmon in Laguna Creek were recorded by plant operators during September or October of this year, despite surface flow

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 24 IS / Proposed ND

continuity likely existing in October. Likewise in other years, reflecting both drier (i.e., 2004 and 2007-2010) and wetter years (i.e., 2005-2006), there has been no observed routine straying into Laguna Creek during the October through December spawning season, despite surface flow continuity beginning in October in all years.

There are a number of factors that explain why straying of fall-run Chinook salmon into Laguna Creek is relatively rare. First, fall-run Chinook salmon arrive and begin holding at the area of tidal influence within the Lower Cosumnes River channel as early as September relatively infrequently. Fall-run Chinook salmon typically don’t begin holding at the upstream-most extent of tidal influence within the Lower Cosumnes River until October in most years (Kennedy pers. comm.). Second, despite the physical depth to swim up into Laguna Creek, the flows contributing to surface flow continuity in September, October, and early November in most years are constituted primarily by American River water, which lacks the olfactory cues to pull in Cosumnes River or Mokelumne River salmon. Only after significant rains have occurred will watershed runoff produce substantial Cosumnes River water in the lower reach of the Cosumnes River channel. Third, the temperature of water flowing within the Lower Cosumnes River channel, between its confluence with Laguna Creek and tide water, during September and October is generally high (e.g., generally >75F until latter October), which is not attractive to adult salmon, compared to the cooler tidal waters. Most of the fish holding in the tidally influenced waters would likely rely on their homing instinct and continue to hold in the cool tidal waters of the Lower Cosumnes River and wait for it to connect, rather than moving upstream into non-natal waters derived from Laguna Creek, even when sufficient passage depths and velocities are present. The combination of improper olfactory cues (i.e., lacking flows originating in the Cosumnes River watershed), low flow rates, and high water temperatures are simply not conducive to attracting fall-run Chinook salmon upstream, which is why such straying into Laguna creek is a relatively rare occurrence.

When the Proposed Project is implemented, these same factors will persist, and a fourth factor will also exist, which is the presence of treated WWTP effluent as part of the flow in September and October. Effluent is present under existing conditions in November based on the WWTP’s current practice of discharging to surface waters November 1 through April 30, annually. Studies conducted by Smith and Bailey (1990) have demonstrated that steelhead, another anadromous salmonid, showed strong avoidance to domestic wastewater effluent. Therefore, adding effluent into the American River water that flows down Laguna Creek and through the portion of the Lower Cosumnes River downstream of Laguna Creek would constitute a fourth factor that is not conducive to attracting adult fall-run Chinook up into Laguna Creek. Rather, the addition of treated effluent to the September and October flow may actually further reduce the already low level of straying into Laguna Creek during these months, relative to existing conditions. When sufficient fall rain events have facilitated surface flow in the mainstem Cosumnes River sufficient to initiate the salmon run to upstream spawning habitats (i.e., greater than 70 cfs at Michigan Bar), the City’s discharge is a very small fraction of the Cosumnes River flow and does not substantially affect the olfactory and other natal-stream cues that trigger salmon migration. This is evidenced by salmon rapidly migrating to upstream spawning grounds annually in November and December when hydraulic continuity throughout the Cosumnes River becomes established, and when WWTP discharges into Skunk and Laguna creeks are occurring.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 25 IS / Proposed ND

At the time when Cosumnes River watershed flows resume following sufficient rains that create surface flow continuity throughout the river, which typically occurs in November or December, annually, the fall-run Chinook salmon that have been holding at the area of tidal influence rapidly migrate up-river to spawning habitats. City WWTP discharges during November and December, when the primary fall-run Chinook salmon spawning migration occurs in the Lower Cosumnes River, would be the same under existing conditions and the Proposed Project. This is because the WWTP already discharges annually during the period November 1 through April 30, and would continue to do so, at the same discharge rates, under the Proposed Project.

Based on the findings discussed above, the Proposed Project would have a less-than significant impact on habitat modifications affecting Cosumnes River fall-run Chinook salmon and would not interfere substantially with the movement of any resident or migratory fish. Finally, the Proposed Project is not expected to increase the rate at which fall-run Chinook salmon stray into Laguna Creek, relative to existing conditions. b, c) Because the Proposed Project adds a relatively small volume of water that complies with applicable water quality standards to the system during the May through October dry season of the year, it would not result in substantial adverse effects on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations or by the California Department of Fish and Game or USFWS. In fact, the Proposed Project is expected to have a net beneficial effect on riparian habitats. Likewise, the Proposed Project would not result in a substantial adverse effect on federally protected wetlands and in fact may have beneficial effects on wetlands receiving water from the Laguna Creek or the Lower Cosumnes River system. e-f) The additional effluent discharged to Skunk Creek, Laguna Creek, and the Lower Cosumnes River during the May through October period will augment flows already occurring in these water body reaches, and may extend surface flow continuity in the Lower Cosumnes River during some months of this period. As such, the Proposed Project would not conflict with any local policies or ordinances protecting biological resources. Moreover, the Proposed Project would not conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 26 IS / Proposed ND

3.6 Cultural Resources

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Cause a substantial adverse change in the significance of a historical resource as defined in Section 15064.5? b) Cause a substantial adverse change in the significance of an archaeological resource pursuant to Section 15064.5? c) Directly or indirectly destroy a unique paleontological resource or site or unique geologic feature? d) Disturb any human remains, including those interred outside of formal cemeteries?

3.6.1 Setting

Based on previous surveys for cultural resources conducted for the City at the WWTP, there are no historical resources listed on or eligible for the California Register of Historical Resources or that meet the definition of “unique archaeological resources” located within or immediately adjacent to the WWTP site.

3.6.2 Discussion a-d) The Proposed Project does not involve any construction or change in operations that would disturb soil. Therefore, no effects on cultural resources are anticipated as a result of implementing the Proposed Project. Therefore, there would be no impact.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 27 IS / Proposed ND

3.7 Geology, Soils, and Seismicity

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation

a) Expose people or structures to potential substantial adverse

effects, including the risk of loss, injury, or death involving:

i) Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault? Refer to Division of Mines and Geology Special Publication 42.

ii) Strong seismic ground shaking?

iii) Seismic-related ground failure, including liquefaction?

iv) Landslides?

b) Result in substantial soil erosion or the loss of topsoil? c) Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially result in on- or off-site landslide, lateral spreading, subsidence, liquefaction or collapse?

d) Be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994), creating substantial risks to life or property?

e) Have soils incapable of adequately supporting the use of septic tanks or alternative wastewater disposal systems where sewers are not available for the disposal of wastewater?

3.7.1 Setting

The project area is located in the Great Valley Geomorphic Province of California, which is a broad structural trough located between the Coast Ranges on the west and the Sierra Nevada on the east, and overlies the Cosumnes groundwater Subbasin (DWR 2006). Soils consist of unconsolidated to semi-consolidated sedimentary deposits (DWR 2006). Soil types underlying the project area consist of San Joaquin-Galt complex, San Joaquin Silt Loam, and Madera Loam (NRCS 2009).

The project area is approximately 70 miles east of San Francisco within Seismic Risk Zone 3, which requires additional earthquake safety building requirements (City of Galt 2005). No active, identified Alquist-Priolo Earthquake Fault Zones are located within the project area (California Department of Conservation 1999) and the nearest active fault, Greenville, is located approximately 42 miles southwest of the City of Galt (City of Galt 2005). The project area would be subject to ground shaking from the active and potentially active faults in the Bay Area. Ground shaking at the project area would depend on the magnitude and location of an earthquake and the project area’s soils.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 28 IS / Proposed ND

3.7.2 Discussion a-e) The Proposed Project involves only implementing year-round discharge of WWTP effluent to Skunk Creek, with a corresponding decrease in the amount of effluent used for irrigation of the RCB property. The Proposed Project does not involve any construction or change in operations that would change or increase exposure to seismic hazards or soil hazards. Therefore, no effects on soil and geological resources are anticipated as a result of implementing the Proposed Project. Therefore, there would be no impact.

3.8 Greenhouse Gases and Climate Change

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Generate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the environment? b) Conflict with any applicable plan, policy, or regulation of an agency adopted for the purpose of reducing the emissions of greenhouse gases?

3.8.1 Setting Section 15150 of the CEQA Guidelines permits documents of lengthy technical detail to be incorporated by reference. Consistent with the CEQA Guidelines and as a way to avoid creating an overwhelming amount of paper for members of the public and decision-makers to sort through, this draft MND incorporates by reference information from both the Existing Conditions Report and Policy Document of the Galt 2030 General Plan. Consistent with this approach, the reader is directed to Chapter 10.8 of the Existing Conditions Report for environmental and regulatory setting information specific to Climate Change.

Climate change research and policy efforts are primarily concerned with the emissions of greenhouse has emissions (GHG) related to human activity that include carbon dioxide, methane, nitrous oxide, tetrafluoromethane, hexafluoroethane, sulfur hexafluoride, HFC-23 (fluoroform), HFC-134a (1, 1, 1, 2–tetrafluoroethane), and HFC-152a (difluoroethane). The City has adopted several polices in the General Plan related to promoting energy conservation and reducing carbon footprint associated with City facilities like the WWTP, including the eventual preparation and adoption of a Greenhouse Gas Emission Reduction Plan (City of Galt 2011). .

3.8.2 Greenhouse Gas Impact Discussion a-b) The Proposed Project would not involve any construction activity or change in WWTP operations that would result in any change to air emissions associated with GHG. Therefore, there would be no impact.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 29 IS / Proposed ND

3.9 Hazards & Hazardous Materials

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials? b) Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment? c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school? d) Be located on a site which is included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5 and, as a result, would it create a significant hazard to the public or the environment? e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard for people residing or working in the project area? f) For a project within the vicinity of a private airstrip, would the project result in a safety hazard for people residing or working in the project area? g) Impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan? h) Expose people or structures to a significant risk of loss, injury or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands?

3.9.1 Setting

Hazardous waste is defined by the California Department of Toxic Substances Control as a waste with properties that make it potentially dangerous or harmful to human health or the environment (Department of Toxic Substances Control 2007). Specifically, hazardous wastes include waste listed on one of the four Resource Conservation and Recovery Act (RCRA) hazardous wastes lists—the F-list (non-specific source wastes), K-list (source-specific wastes), P-list and U-list (both lists consist of discarded commercial waste products), or that exhibits one of the four characteristics of a hazardous waste—ignitability, corrosivity, reactivity, or toxicity.

3.9.2 Discussion a-h) The Proposed Project does not involve any construction or change in operations that would change the use of any hazardous materials or affect or generate hazardous wastes. Therefore, no effects on

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 30 IS / Proposed ND

hazards and hazardous materials are anticipated as a result of implementing the Proposed Project. Therefore, there would be no impact.

3.10 Hydrology and Water Quality

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Violate any water quality standards or waste discharge requirements? b) Substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table level (e.g., the production rate of pre-existing nearby wells would drop to a level which would not support existing land uses or planned uses for which permits have been granted)? c) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, in a manner which would result in substantial erosion or siltation on- or off-site? d) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or substantially increase the rate or amount of surface runoff in a manner which would result in flooding on- or off- site? e) Create or contribute runoff water which would exceed the capacity of existing or planned storm water drainage systems or provide substantial additional sources of polluted runoff? f) Otherwise substantially degrade water quality? g) Place housing within a 100-year flood hazard area as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map? h) Place within a 100-year flood hazard area structures which would impede or redirect flood flows? i) Expose people or structures to a significant risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam? j) Inundation by seiche, tsunami, or mudflow?

3.10.1 Setting

Environmental Setting The City of Galt is located in a Mediterranean climate with dry, warm summers and cool, wet winters. Annual precipitation in the City vicinity is approximately 17.7 inches, with most occurring from November through March (Western Regional Climate Center 2005).

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 31 IS / Proposed ND

Surface Water The project area is located in the Cosumnes River watershed hydrologic area, which is a subunit of the San Joaquin hydrologic region. The existing WWTP currently discharges treated effluent from its surface reservoir into a remnant section of Skunk Creek during the period of November through April. Effluent is conveyed approximately 0.6 miles in Skunk Creek at which point it is a tributary to Laguna Creek, which is a tributary to the Lower Cosumnes River. The Lower Cosumnes River is tidally influenced approximately 1.5 to 2.0 miles downstream of its confluence with Laguna Creek. The Cosumnes River joins the Mokelumne River within the Delta, approximately 5 miles downstream of the WWTP. The lower approximately 25 miles of the Cosumnes River channel is typically dry, or contains discontinuous segments of wetted conditions, during the summer dry months (Mount et al. 2001). Laguna Creek flows are supplemented by year-round discharges from Sacramento Municipal Utilities District’s (SMUD) Rancho Seco decommissioned nuclear power generating facility, which discharges roughly 20 cubic feet per second (cfs) into Hadselville Creek. Hadselville Creek joins Laguna Creek approximately 10.5 miles upstream of where the WWTP effluent enters Laguna Creek. During the irrigation season, typically May through October, riparian users divert nearly all the flow in Laguna Creek for irrigation. As such, it is anticipated that little flow reaches the lower portion of Laguna Creek west of Highway 99 near the WWTP during the peak summer irrigation periods. Starting in January 2009, Weekly Laguna Creek streamflow monitoring has been conducted by the City’s WWTP staff immediately upstream of Skunk Creek. At that point, the water levels have been frequently lower than the lowest staff gage reading of 3 cfs. However, even that channel has not been observed to be completely dry at any time. Analysis of aerial photographs conducted for the assessment of effects to biological resources (i.e., fisheries, see Section 3.5) indicates that continuous streamflow from Laguna Creek to the tidally influenced area of the Lower Cosumnes River can be observed in all photos that were obtained for the May through October period, which included several drier year-type conditions (i.e., September 2010, August 2008, and July 2004) and other year-types. The Regional Water Board has established beneficial uses for the Cosumnes River as: agricultural supply, municipal and domestic supply, contact and non-contact recreation, warm and cold freshwater habitat, warm and cold migration, warm and cold spawning habitat, and wildlife habitat (Central Valley Regional Water Quality Control Board 2009). These beneficial uses would also apply to the river’s tributary streams. Available information characterizing existing water quality conditions in Laguna Creek is limited to the routine monitoring data collected by the WWTP operators for general parameters such as temperature, dissolved oxygen (DO), electrical conductivity (EC), pH, turbidity, and ammonia at locations upstream (R1) and downstream (R2) of the WWTP. Because effluent historically has not been discharged during May through October, the receiving water data is not collected during those months. However, the City conducted a 12-month study of metals and selected other constituents in the receiving water during the period of April 2007-March 2008, thus providing a limited data set upon which to understand dry season conditions in Laguna Creek.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 32 IS / Proposed ND

There also is no entity that conducts routine water quality monitoring of the Cosumnes River, thus available information is limited. Based on available data, the water quality of the Cosumnes River is designated as impaired by the Regional Water Board for exotic species on the 2006 Clean Water Act Section 303(d) list of water quality limited stream segments (State Water Resources Control Board 2007). The SRWCB approved new revisions to the 303(d) list in October 2010, which are awaiting approval by EPA. If approved, the Cosumnes River will also be listed as impaired for Eschericia coli (E. coli) bacteria and sediment toxicity, both resulting from unknown sources. Laguna Creek is not identified as water quality limited on either the 2006 or 2010 Section 303(d) lists. Effluent discharges to Skunk Creek from the WWTP are regulated by the Central Valley Regional Water Board under the City’s WDRs/NPDES permit (Order No. R5-2010-0099, NPDES No. CA0081434), which was renewed September 23, 2010. The NPDES permit regulates the allowable concentrations and loadings of constituents that have the potential to affect beneficial uses of the receiving water so that the discharge complies with all applicable water quality standards.

Groundwater The project area is located in the Cosumnes Subbasin of the San Joaquin Valley Groundwater Basin. The groundwater quality of the Cosumnes Subbasin is characterized by calcium- magnesium or calcium-sodium bicarbonate types (DWR 2006). The sub-basin’s water quality has been impaired in some locations for pesticides (DWR 2006). Groundwater levels in the subbasin are generally at the mid-1980s levels (DWR 2006). Historic groundwater levels near the project area ranged from approximately 76 to 96 feet below the land surface (DWR 2009).

3.10.2 Discussion a) The proposed discharge of effluent to Skunk Creek during the period of May 1 through October 31 annually would change the hydrology and water quality conditions in Skunk Creek, Laguna Creek, and the Lower Cosumnes River compared to existing conditions. This assessment incorporates by reference information and analysis of constituent characteristics of the effluent discharge (e.g., maximum observed concentrations, frequency of occurrence), and resulting effects to receiving water quality, that were presented in an antidegradation analysis prepared by Robertson-Bryan, Inc. (RBI 2009) for the City’s NPDES/WDRs permit renewal process. The antidegradation analysis assessed the Proposed Project conditions of 3.0 MGD effluent discharge with tertiary filtration, UV disinfection, and fully nitrified effluent (identified in the antidegradation report as the “Interim Phase 1” scenario). The antidegradation analysis considered potential dilution that would be provided by Laguna Creek using the calculated design minimum streamflow rates specified by state policy (i.e., 0.1 cfs for the 1-day average low flow with recurrence interval of once in 10 years [1Q10] for acute conditions, and 0.2 cfs for a 7-day average/10-year low flow [7Q10] for chronic conditions). This assessment also considered the most recent effluent constituent monitoring data available since the tertiary filtration and UV disinfection system upgrades were completed and became fully operational in January 2011.

Concentrations of constituents in WWTP effluent were evaluated in relation to applicable water quality objectives including California Toxics Rule (CTR)/National Toxics Rule (NTR) criteria,

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 33 IS / Proposed ND

Basin Plan water quality objectives, and state drinking water maximum contaminant levels (MCLs), which the Basin Plan incorporates by reference as water quality objectives. In cases where adopted state water quality objectives do not exist (e.g., ammonia), EPA-recommended criteria or other literature-based values are used. The evaluation consisted of determining whether the constituent had been detected in the WWTP effluent and how substantial the detected maximum concentration was. For the purposes of assessing the potential for project operations to exceed the threshold of significance, the term “violate” is defined as changes that are of sufficient frequency, magnitude, and geographic extent to adversely affect a beneficial use of a water body. If consistent compliance with the applicable water quality criteria/objectives was demonstrated for the receiving water downstream of the WWTP effluent discharge, or if beneficial uses would not be adversely affected, then it was determined that the project-related discharges would not adversely affect water quality.

WWTP effluent monitoring data generally falls into one of three categories:

• Constituents detected in the effluent one or more times; • Constituents not detected in the effluent, and at least one sample detection limit is less than applicable water quality criteria values; and • Constituents not detected in the effluent, and all detection limits are greater than applicable water quality criteria values.

Constituents were evaluated further in this IS if they were detected at least once in the WWTP effluent at levels above applicable water quality criteria or other relevant guidance values (e.g., EPA-recommended criteria). Constituents that have not been detected in the WWTP effluent (e.g., trace organic compounds), and the best commercially available laboratory analytical detection limits exceed the applicable criteria, were not carried forward for further analysis because no relevant assessment of the presence or concentration of these constituents can be conducted, thus an informed impact determination cannot be made. Constituents that have never been detected at or above a laboratory detection limit that is less than the applicable water quality criteria, and constituents that have been detected only at levels below applicable water quality criteria or other relevant guidance values, were not evaluated further because adverse effects to beneficial uses would not be expected to occur when constituent concentrations are consistently below water quality criteria or other relevant threshold values. However, constituents detected in the effluent at a maximum concentration that exceeded the minimum receiving water (R1) concentration were evaluated further for the potential to degrade existing water quality conditions (see discussion below regarding potential degradation under checklist question “f”). Additionally, pursuant to provisions of the NPDES permit and other regulations concerning WWTP design and operation (e.g., EPA technology based performance requirements), the WWTP must meet water quality standards for conventional wastewater parameters including biochemical oxygen demand (BOD), pH, TSS, settleable solids, and turbidity. Thus, compliance for these constituents is not assessed further in this IS.

Anticipated recent changes in effluent quality associated with the completion of the tertiary filtration and UV disinfection upgrades, and operations for improved nitrification performance are considered in this impact assessment. Available monitoring data collected since January 2011 indicates that the effluent concentrations for several constituents have decreased following implementation of the upgrades, as anticipated in previous design studies. The WWTP reduces

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 34 IS / Proposed ND

ammonia levels through operations management to improve nitrification processes, which are anticipated to reduce ammonia to less than 0.7 mg/L-N on a monthly average basis and less than 2.0 mg/L-N on a daily average basis (West Yost Associates 2009). The City prepared an ammonia compliance work plan following the renewal of the NPDES permit that identifies actions the City is taking to comply with effluent limitations (Carollo 2011a). The ammonia workplan indicates effluent ammonia concentrations with operation of the effluent bypass pipeline since November 2009 have averaged 1.08 mg/L-N with a maximum daily of 2.5 mg/L-N. The current ammonia levels are less than the applicable EPA-recommended criteria and the current effluent limitations in the NPDES permit, and continued treatment performance and compliance with ammonia effluent limitations is anticipated. The elimination of the former chlorine disinfection system and subsequent conversion to UV disinfection has eliminated production of trihalomethane compounds (THMs). Discontinuing the use of chlorine-based disinfection and dechlorination chemicals also is anticipated to reduce salinity parameters (i.e., total dissolved solids [TDS] and electrical conductivity [EC]). The current TDS/EC levels in the effluent are compliant with applicable water quality standards. The improved solids-removal performance of the new tertiary filters also will reduce turbidity and concentrations of total suspended solids (TSS). Improved solids removal also may reduce concentrations of constituents that can be associated with solids through physical or chemical binding, such as some inorganic elements (e.g., iron, manganese, phosphorus) and particulate-bound trace metals and organic compounds.

Historical detections in effluent for bis(2-ethlyhexyl)phthalate and carbon tetrachloride are not considered further in this analysis. All detections for bis(2-ethlyhexyl)phthalate in the Laguna Creek and effluent samples coincided with simultaneous detections in field blanks. Thus, the City suspects that bis(2-ethylhexyl)phthalate was not actually present in the samples or at the levels measured. Bis(2-ethlyhexyl)phthalate is a compound widely used in the plastics industry and is recognized as potential cross-contaminant that can enter a water sample during sample collection, handling, storage, and laboratory analytical procedures. Using clean sampling and handling methods, bis(2-ethlyhexyl)phthalate has not been observed in the effluent since November 2009. Carbon tetrachloride has been detected only once, which was below the laboratory’s ability to quantify the concentration. Thus, it was reported with an estimated concentration of 2.5 µg/L, which is above the applicable CTR human health criterion. Carbon tetrachloride has never been detected in the WWTP influent, thus, the single detection was likely a byproduct formed via the former chlorine disinfection process, or a laboratory error. With the new UV disinfection system and the elimination of chlorine, the potential for carbon tetrachloride formation no longer exists.

Based on the available effluent data for individual samples, and with the anticipated effluent quality improvements resulting from completion the WWTP upgrades, it is anticipated that the undiluted effluent may exceed the lowest applicable water quality criteria for aluminum, arsenic, copper, cyanide, iron, and nitrate. Undiluted effluent concentrations of ammonia, nitrite, total phosphorus, salinity (i.e., EC and TDS), and zinc are lower than applicable criteria/objectives, but may exceed the background receiving water concentration in Laguna Creek, and thus may contribute to degradation of water quality in the receiving water (Note: see discussion under checklist question “f” regarding these latter constituents).

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 35 IS / Proposed ND

Detailed discussion is provided below for each constituent and the potential project-related effects to beneficial uses that criteria are established to protect. The assessment considers dilution provided by Laguna Creek and Lower Cosumnes River flows in reducing the magnitude of concentration change. Potential changes in receiving water concentrations also are assessed with respect to appropriate averaging periods on which the criteria are based. That is, aquatic life are generally less able to tolerate concentration changes and criteria are based on a maximum allowable change over a short averaging time period (e.g., 1-hour for acute criteria and 4-day averaging for chronic criteria). Human health criteria often reflect the maximum tolerable value for longer averaging periods (e.g., lifetime exposure for many constituents of concern in drinking water supplies) In particular, based on appropriate averaging of values, the potential project-related discharges of aluminum and iron are not considered further in this assessment of the potential to exceed applicable water quality criteria. While the undiluted effluent may exceed aluminum and iron criteria on an infrequent basis, the average effluent concentrations of aluminum (i.e., 69 µg/L) and iron (112 µg/L) are well below their respective secondary drinking water maximum contaminant levels (MCLs) of 200 µg/L and 300 µg/L. Consequently, the discharge of these constituents in undiluted effluent is not expected to adversely affect receiving water quality or beneficial uses.

The remainder of this assessment addresses those constituents that may exceed applicable criteria/objectives in the undiluted effluent, and for which the City is continuing to resolve the regulatory compliance issues identified in the NPDES permit. Following renewal of the NPDES permit, the City prepared a work plan to identify actions that will be taken to resolve the remaining regulatory compliance issues (Carollo 2011b).

Arsenic. Arsenic historically has been elevated in the City’s groundwater supply relative to the EPA-recommended primary drinking water MCL of 10 µg/L, resulting in WWTP effluent concentrations exceeding the MCL on both an individual sample and average monthly basis. In March of 2009, the City began implementing wellhead treatment to reduce the concentrations of arsenic in drinking water supplies (Carollo 2011b). The existing water treatment system provides iron and manganese removal using a variety of greensand and proprietary filtration systems. Wellhead treatment is being implemented for all but one well, which is out of service until its treatment system is complete (anticipated January 2012). It is believed that the precipitation process at the wellhead also may create a more filterable form of arsenic, which can be more effectively removed in the WWTP. Additionally, the City investigated alternate groundwater resources that do not contain actionable levels of arsenic as a pollution prevention measure, and has now added one deeper, low-arsenic well to the supply system which is anticipated to further enable achieving compliance with arsenic effluent limitations.

Considering available average dilution provided in the receiving water (Laguna Creek), the effluent discharge under the Proposed Project is anticipated to result in Laguna Creek arsenic concentrations that remain below the primary drinking water MCL. Moreover, Laguna Creek is not currently being used for domestic or municipal water supply (MUN), nor is it expected to be used as such in the near future. With continued implementation and refinement of the wellhead treatment systems for arsenic removal, the effluent arsenic levels are anticipated to ultimately decline and remain below the MCL, thus further ensuring protection of any potential future MUN use of Laguna Creek waters, should such use occur. Therefore, based on the available information, the discharge of

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 36 IS / Proposed ND

arsenic under the Proposed Project would not result in substantial frequency, duration, or regional extent of exceedance above the MCL or cause adverse effects to beneficial uses downstream of the discharge. Therefore, the potential long-term operations-related water quality impacts of the Proposed Project due to arsenic discharge would be less than significant.

Copper. At a maximum observed effluent concentration of 5.4 µg/L, the discharge of copper under the Proposed Project may exceed the applicable CTR chronic aquatic life criterion of 3.3 µg/L. The Basin Plan objective for total copper in Delta waters downstream of the discharge is 10 µg/L, and CTR human health criterion is 1,300 µg/L. Average effluent copper concentrations are now believed to be lower with the completion of the effluent pipeline bypass system in 2009, which allows direct discharge of effluent to Skunk Creek from the WWTP (Corollo 2011b). Prior to this upgrade, treated effluent was directed through the effluent storage reservoir, which is believed to have caused elevated copper levels as a result of sediment re-suspension within the reservoir. Utilization of the pipeline bypass system is expected to prevent spikes in effluent copper levels. Since operations of the bypass pipeline began in November 2009, average effluent copper levels have declined (Corollo 2011b).

The CTR chronic and acute criteria for the protection of aquatic life apply to the dissolved fraction of copper in water and the criteria are derived with a hardness-dependent equation to reflect that sensitivity of aquatic life to copper (i.e., toxicity) increases as the water’s hardness decreases. Many aspects of water chemistry such as concentrations of dissolved organic carbon, calcium, sodium, dissolved inorganic carbon (or alkalinity), magnesium, sulfate, chloride, potassium, and pH affect copper “bioavailability.” Bioavailability is a term used to refer to the fraction of total measured copper in water that is in a form capable of being taken up into the bodies of fish (across gill membranes) and other aquatic life. The most bioavailable, and thus toxic, form of copper is the free ion. Non-bioavailable forms of copper, although measured analytically in a total recoverable and dissolved measurements, are forms where the free copper ion is bonded to carbonates, large organic molecules, or particles, thus making the copper complex too large to be taken up across membranes of organisms. Copper within the water column that is not biologically available for uptake by aquatic life is nontoxic to the aquatic life.

To address the toxicological reality of bioavailability with regard to copper, the CTR criteria include a water-effect ratio (WER) multiplier. The WER accounts for the effects of all aspects of water chemistry on bioavailability and thus toxicity, and is a more comprehensive mechanism for addressing copper bioavailability than simply expressing the criteria in terms of the dissolved fraction. The WER is a measure of the water’s ability to form complexes with the toxic free copper ions, thereby making them biologically unavailable and nontoxic to aquatic life. A WER value of 1.0 means that the water body has no more capacity to bind free copper ions (the most toxic form of copper) than the laboratory waters used in deriving the unadjusted CTR criteria. A WER value of 2.0 means that that water requires twice the copper concentration, relative to the EPA laboratory water used to derive the unadjusted criteria, to have the same toxic effect on aquatic life. For regulatory (e.g., NPDES permitting) purposes, the WER is assumed to be 1.0, unless site-specific data are developed that rebut this presumption, and a site-specific or discharger-specific WER other than 1.0 is found to be appropriate for the site, based on site water chemistry.

Effluent from municipal WWTPs contains dissolved organic matter and inorganic constituents that are effective at binding the free copper ions, thereby increasing the WER above 1.0 for sites

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 37 IS / Proposed ND

influenced by WWTP discharges. Copper WER values for undiluted, biologically treated municipal effluent have frequently been shown to range from about 3 to 30, and even higher (El Dorado Irrigation District 2008, Hall et al. 1997). The 3.3 µg/L CTR chronic criterion used for the City’s NPDES permit is based the lowest effluent water hardness of 52 mg/l and an assumed WER of 1.0 (i.e., unadjusted for the site-specific WER). Because the WER adjustment was not performed, the criteria applied to the City’s permit are overly conservative for protection of aquatic organisms in the receiving water. Considering the minimum WER of 3.0 observed in literature and based on Central Valley discharger experience, a reasonably conservative chronic criterion for the Proposed Project is estimated to be 9.9 µg/L (i.e., 3.3 µg/L x 3.0 WER). Moreover, for the purposes of assessing compliance with criteria, EPA intended for copper criteria to be hardness- adjusted at the time of measurement rather than comparing measured copper concentrations to a static criteria based on the lowest hardness ever recorded. Thus, for all other hardness levels in the effluent, the appropriately protective criteria for the City’s effluent would be higher.

Based on this assessment, the maximum observed effluent copper concentration of 5.4 µg/L for Proposed Project would always be below the conservative WER-adjusted acute and chronic criteria of 9.9 µg/L and 13.5 µg/L, respectively. Thus, the effluent discharge to Skunk Creek/Laguna Creek, when little to no receiving water streamflow exists, would not cause copper toxicity to aquatic life that exist within the creeks downstream of the discharge. Therefore, based on the available information, the discharge of copper under the Proposed Project would not result in substantial frequency, duration, or regional extent of exceedance above the CTR criteria to cause adverse effects to beneficial uses downstream of the discharge. Therefore, the potential long-term operations-related water quality impacts of the Proposed Project due to copper discharge would be less than significant.

Cyanide. Cyanide has only been observed once (April 2007) in the undiluted WWTP effluent at a concentration exceeding the 5.2 µg/L CTR chronic criterion for aquatic life protection. With dilution in Laguna Creek, receiving water concentrations of cyanide should remain below the criterion. Cyanide has never been detected in the WWTP influent, and all other effluent samples have been lower than applicable regulatory criteria with no detections in the effluent since November 2009 (Carollo 2011b). Cyanide can be formed by chlorine disinfection, and thus the elimination of the former chlorine disinfection system has reduced the potential for cyanide formation in effluent. Additionally, the current approved methods for total cyanide analyses are known to be affected by interferences associated with sample preservation and pre-treatment procedures which can cause false positive results. The U.S. EPA released proposed amendments to 40 CFR Part 136 regulations defining the approved analytical methods for cyanide. The proposed amendments provide for the use of modified methods for the purposes of assessing compliance with NPDES permits that are intended to reduce the probability of causing false positive results. Final adoption of the 40 CFR Part 136 amendments for cyanide analysis are uncertain, but not anticipated before mid-2011.

Based on the low frequency of detection historically, and probability that detection was associated with either the chlorination system or the standard preservation method, there is substantial evidence that the effluent discharge under the Proposed Project would not result in exceedance of applicable criteria in the receiving water, or otherwise adversely affect beneficial uses, downstream of the discharge. Therefore, the potential long-term operations-related water quality impacts of the proposed project due to cyanide discharges would be less than significant.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 38 IS / Proposed ND

Nitrate. The WWTP generally provides full nitrification of the effluent, converting nitrogen compounds to either nitrite or nitrate, however, nitrite levels tend to be low because it is rapidly oxidized in water to nitrate. Because denitrification capacity of the WWTP processes is limited, nitrate levels are elevated relative to the state primary drinking water MCL of 10 mg/L (as N). Nitrate and nitrite are a concern to human health, particularly for infants and fetuses at levels exceeding the MCL because they can interfere with oxygen and hemoglobin functions in the blood, causing a condition called methemoglobinemia.

Prior to the completion of the effluent pipeline bypass project, spikes in effluent nitrate levels were known to occasionally occur as effluent passed through the effluent storage reservoir. Since November 2009, effluent nitrate levels have averaged 6.8 mg/L with the maximum observed value of 13.0 mg/L. The maximum nitrate concentration in Laguna Creek is 0.67 mg/L with an average concentration of 0.14 mg/L (2005-2008 data assessed in the antidegradation analysis). Thus, there is assimilative capacity for nitrate in Laguna Creek; however, dilution is low during the May through October period due to low streamflow conditions. There is the potential that the discharge would cause occasional, short-term exceedance of the nitrate MCL in Skunk Creek/Laguna Creek and further downstream.

The current average nitrate concentration is less than the MCL, thus effluent discharge under the Proposed Project would not result in water sources having nitrate levels above the MCL over relevant exposure time periods to substantially increase the risks of health effects. Dilution in the receiving water and dispersion in the groundwater would result in further reductions in nitrate concentration downstream of the discharge. Moreover, Laguna Creek is not currently being used for domestic or municipal water supply (MUN), nor is it expected to receive such use in the near future.

Additionally, based on assessment of aerial photographs, the flow in Laguna Creek is partially impeded at its confluence with the Lower Cosumnes River channel, resulting in ponding of water upstream of this barrier. Review of aerial photographs indicate that the partially impounded water in the Laguna Creek channel exhibits profuse growth of vascular aquatic plants that can cover the entire channel during summer months. Nitrate is a primary nutrient that aquatic plants can use, and their presence may further reduce nitrate in the streamflow as it moves downstream through the plants.

The discharge of effluent with potentially elevated nitrate levels will be temporary, as the City intends to add denitrification capacity to the WWTP under the future expansion project. Additional denitrification capacity will reduce effluent nitrate concentrations to ensure compliance with the primary drinking water MCL and the NPDES permit final nitrate effluent limitations. In addition to ensuring compliance with anticipated final nitrate effluent limitations, the denitrification facilities will ensure protection of potential future MUN use of Laguna Creek waters, should such use occur, downstream of its confluence with Skunk Creek. Therefore, based on the available information, the discharge of nitrate under the Proposed Project would not result in substantial frequency, duration, or regional extent of exceedance above the MCL to cause adverse effects to beneficial uses downstream of the discharge. Therefore, the potential long-term operations-related water quality impacts of the Proposed Project due to nitrate discharge would be less than significant.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 39 IS / Proposed ND

Nutrients (Nitrogen and Phosphorus). Nitrogen and phosphorus are water quality constituents of concern in streams based in part on their important role as nutrients for plants such as planktonic and benthic algae, and vascular aquatic macrophytes. In particular, elevated concentrations of nutrients can contribute to biostimulation of algae and vascular plants, which in turn can contribute to several nuisance conditions:

• aesthetically undesirable conditions for recreational users;

• tastes and odors in supplies of drinking water;

• daily changes in DO and pH levels in response to algal photosynthesis (day) and respiration (night) cycles; and

• potential algal toxin production and release, primarily by blue-green algae species, which can be harmful to animals and humans.

Nitrogen is often considered the limiting nutrient in flowing streams, as opposed to other potential limiting factors such as light or phosphorus (EPA 2000). Numerical criteria have not been developed for the purpose of limiting biostimulatory responses in aquatic ecosystems, however, the Basin Plan contains a narrative water quality objective to require that discharges do not cause biostimulation that would adversely affect beneficial uses. A major difficulty in the science of biostimulation is that the variety and magnitude of specific factors affecting algae and plant growth can vary greatly among varying habitat types. EPA, in promoting the development of ecoregional nutrient criteria for streams, considers it more appropriate to classify the trophic states of stream systems based on benthic algal biomass (e.g., chlorophyll per unit area) than on in-water nutrient concentrations (EPA 2000).

The City’s WWTP effluent contains elevated nitrogen and phosphorus concentrations relative to the Laguna Creek receiving water. Consequently, it is anticipated that the effluent discharges under the Proposed Project could contribute to nutrient biostimulation of primary production in the receiving waters downstream of the discharge. However, as noted above, assessment of aerial photographs of the Laguna Creek channel taken in the months of the proposed discharge indicate that the channel currently experiences profuse and dense aquatic vegetation growth under existing conditions. Consequently, the visual evidence suggests that nutrient levels in Laguna Creek are sufficiently elevated under existing conditions to stimulate plant growth. Thus, the additional nutrient discharge under the Proposed Project would not be expected to increase biostimulation conditions because nutrients are not currently limiting in these creeks. Based on available data, it is anticipated that the effluent nutrient discharges under the proposed project would not substantially change the existing biostimulation conditions, and thus would not adversely affect beneficial uses. Therefore, the potential long-term operations-related water quality impacts of the proposed project due to nutrient discharges would be less than significant.

Constituents of Emerging Concern. Several classes of compounds are considered constituents of emerging concern (CECs) when discharged in domestic wastewater: pharmaceutical and personal care products (PPCPs), natural and synthetic hormones, alkylphenols and alkylphenol ethoxylates, polybrominated diphenyl ether flame-retardant chemicals, bisphenol A, and new unregulated pesticides. Some classes of contaminants (e.g., PPCPs and hormones) are recognized as endocrine- disrupting compounds (EDCs) that have the potential to cause or contribute to adverse water quality

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 40 IS / Proposed ND

effects on aquatic organisms. No applicable federal water quality criteria or state objectives have been adopted or recommended for the suite of CECs, and it may be many years before regulatory objectives are developed or the state’s regional water quality control boards establish effluent limitations for CECs in wastewater discharges. The existing WWTP effluent has not been monitored for CECs, nor has monitoring been required. Consequently, this assessment is provided for informational purposes and, at this time, there is not sufficiently developed scientific evidence available to assess the specific environmental effects of CECs in the Proposed Project discharges on beneficial uses in downstream receiving water bodies.

EDCs are substances or mixtures that alter the function of the endocrine system and consequently cause adverse health effects in an intact organism or its progeny (WHO 2002). Endocrine disruption may be described as a functional change that may lead to adverse effects, not necessarily a toxicological end point. Most EDCs are human-made synthetic chemicals, such as hormones or other drugs that are released into the environment unintentionally (e.g., as trace elements in human urine that are not removed by conventional wastewater treatment). EDCs may block, mimic, stimulate, or inhibit the production of natural hormones, disrupting the endocrine system’s natural functions. The endocrine system is a complex of glands that secrete hormones and regulate reproduction, growth, and development in vertebrates. Certain drugs, such as birth control pills, intentionally alter the endocrine system. Although some EDCs are known, many chemicals are termed “suspect” because they have not been sufficiently evaluated to allow a conclusive determination of their endocrine-disrupting characteristics.

The potential ecological effects of EDCs in the aquatic environment were first reported in the 1990s. Studies suggested that the presence of natural and synthetic estrogen hormones in wastewater induced the production in male fish of vitellogenin, which is a protein involved in reproduction that is normally found only in females (Desbrow et al. 1998). Similar results were observed with alkylphenolic compounds, which are breakdown products of industrial surfactants used in products such as paints, herbicides, and cosmetics (Jobling et al. 1998). The U.S. Geological Survey (Barnes et al. 2002) found the occurrence of EDCs or potential EDCs to be high in surface waters across the country, with 80% of the streams sampled containing at least one of the 95 endocrine-disrupting compounds that were tested. Although the frequency of occurrence was relatively high, measured concentrations of EDCs were low, usually below drinking-water standards for compounds that have such standards.

Human exposure and dose response to EDCs in concentrations at the low levels found in the environment is still largely unknown. The absence of adequate exposure data, especially data regarding exposure during critical development periods, is the weakest link in determining whether any observed adverse effects on humans and/or fish and wildlife are linked to EDCs. The World Health Organization’s state-of-the-science assessment concludes that “…our current understanding of the effects posed by EDCs to wildlife [including fish] and humans is incomplete” (WHO 2002). The National Toxicology Program’s draft report on the Endocrine Disruptors Low-Dose Peer Review was released for public comment in May 2001 (66 FR 27152, May 16, 2001). As stated in this report, “the focus of this review was on ‘biological change’ rather than on ‘adverse effect’ because, in many cases, the long-term health consequences of altered endocrine function during development have not been fully characterized.”

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 41 IS / Proposed ND

Some known EDCs (e.g., polychlorinated biphenyls [PCBs], dichlorodiphenyltrichloroethane [DDT], and chlordane) are regulated via ambient water quality criteria or drinking-water standards based on their toxicological and carcinogenic effects. However, there are no applicable water quality criteria for natural and synthetic estrogens or related pharmaceutical chemicals. Based on the current state of knowledge regarding dose-response relationships of CECs for various organisms at the low levels in which they can occur in surface waters, it is likely to be many years before any such standards are promulgated. The approach in the United States has been to require more definitive information to be gathered and conclusive research conducted before regulatory measures can be taken.

Municipal WWTPs are not specifically designed to treat and remove CECs, but activated sludge treatment processes are known to be effective in CEC treatment and removal. The Water Environment Research Foundation has sponsored research that investigated factors of WWTP processes that remove PPCPs (Oppenheimer and Stephenson 2006). The study evaluated monitoring data for 20 PPCP compounds in a variety of secondary biological and filtration treatment processes, including processes with nitrification and denitrification. The study determined that in general, an increase in solids residence time (SRT) was an important factor that enhanced removal efficiency for the majority of the monitored chemicals. The SRT required to achieve consistent removal above 80% is compound-specific, with many of the target compounds well removed by activated sludge processes with SRTs of 5–15 days. Half of the 20 PPCP target compounds frequently occurred in secondary influent, but were also efficiently removed (> 80%) at SRT of less than 5 days: caffeine, ibuprofen, oxybenzone, chloroxylenol, methylparaben, benzyl salicylate, 3-phenylpropionate, butylbenzyl phthalate, and octylmethoxycinnamate. An SRT of more than 30 days was necessary to achieve 80% removal for certain compounds.

Miège et al. (2009) evaluated PPCP removal performance based on monitoring data from 117 WWTPs and determined that removal efficiency was highest in facilities using activated sludge with nitrogen removal processes. They determined that the main mechanisms involved in PPCP removal efficiency were biodegradation (e.g., oxidation, hydrolysis, demethylation, cleavage of glucuronide conjugates), sorption on sludge or particulate matter (by hydrophobic or electrostatic interactions), and filtration.

The unit processes proposed for the City’s WWTP are not specifically designed to treat and remove CECs. However, the WWTP includes treatment technologies that are known to enhance treatment and removal performance for CEC compounds. In particular, the WWTP provides extended- aeration activated sludge processes with long hydraulic detention time and SRT. Because there are no current regulatory criteria against which to evaluate concentrations of CECs in effluent, a significance conclusion on the environmental impacts of CEC discharges under the Proposed Project cannot be made. Section 15145 of the State CEQA Guidelines provides that if, after a thorough investigation, a lead agency finds that a particular impact is too speculative for evaluation, the agency should note its conclusion and terminate discussion of the impacts. This is the case for CECs that may be present in the City’s WWTP effluent. Based on the current state of knowledge about this topic, no impact conclusion can be made about CEC levels in the WWTP effluent or any potential water quality effects of the discharge on beneficial uses in the receiving water bodies.

Temperature. The Proposed Project would result in year-round effluent discharge operations to Skunk Creek/Laguna Creek, which would create permanent aquatic habitat for the warmwater fish

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 42 IS / Proposed ND

community downstream of the WWTP outfall. However, because the City is not required to monitor temperatures from May through October, the period during which it does not currently discharge, there are no data available for these months. Most importantly, this is the period during which the maximum annual creek temperatures would occur. An examination of other wastewater dischargers in the Central Valley indicate that effluent temperatures are typically well within the thermal tolerance range of warmwater fishes occurring in the Central Valley. For example, effluent temperatures for the City of Lodi’s White Slough Water Pollution Control Facility (WPCF) average approximately 78ºF and rarely exceeds 81ºF during the months of July and August. Similarly, temperatures for the Flag City WWTP effluent averaged approximately 79ºF and rarely exceeded 81ºF during July 2005, one of the warmest months (99th percentile) on record since 1931. Consequently, it can reasonably be assumed that the Galt WWTP effluent would have similar maximum summertime temperatures.

Because flow in Skunk Creek and Laguna Creek (downstream of the WWTP) will be dominated by the WWTP discharge during the summer months, the temperature of Skunk Creek would be the same as the effluent at the point of discharge, but become more variable as it flows downstream and becomes increasingly affected by ambient air temperatures and solar radiation. Ultimately, the summer temperature regime of Laguna Creek would likely become similar to those of other streams of the Central Valley, which support diverse communities of warmwater fishes. Consequently, the temperature regime under Proposed Project conditions would not adversely affect the warmwater aquatic communities in Laguna or Skunk creeks or otherwise have adverse population-level effects on the warmwater species of these creeks. These creeks do not support a coldwater species or communities during the summer months.

Given the large amount of dilution available in the tidally influenced reach of the Lower Cosumnes River coupled with the tidal action that would serve to mix the incoming creek flows, any increases in temperature in the Cosumnes River that would result from the Proposed Project would be negligible and would be restricted to a small area near the interface of incoming creek flows and tidewater. Consequently, the Proposed Project would not be expected to have adverse temperature- related effects on anadromous salmonids or their habitat in the lower Cosumnes or Mokelumne rivers during their early migration period. Therefore, based on the available information, the Proposed Project would not result in substantial temperature changes in the receiving waters at a frequency, duration, or regional extent to cause adverse effects to beneficial uses downstream of the discharge. Therefore, the potential long-term operations-related temperature impacts of the Proposed Project would be less than significant.

Dissolved Oxygen. In aquatic environments, dissolved oxygen (DO) reduction can occur in relation to increased biochemical oxygen demand (BOD), including oxidation of ammonia to nitrite and nitrate. Oxygen input to a stream from physical mixing and reaeration processes and photosynthesis of aquatic plants tends to offset the oxygen demand of WWTP effluent as it flows downstream. The project-related discharge would increase BOD and ammonia loading to Skunk Creek and Laguna Creek from May through October, thereby potentially resulting in a lowering of water quality with respect to DO.

The NPDES permit contains the following receiving water DO limitations, which are derived from the Basin Plan objective for DO, restricting the WWTP’s effects on Laguna Creek DO (as measured at R2):

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 43 IS / Proposed ND

• A daily minimum limitation of 7.0 mg/L on a daily basis, • A monthly median limitation of 85% saturation, and • A 95th percentile minimum limitation of 75% saturation.

Historical discharge season DO monitoring data collected in Laguna Creek (at R2) between April 2004 and March 2008 were evaluated in the Report of Waste Discharge (ROWD) submitted for the NPDES permit renewal process, indicating an 82% compliance rate with the daily minimum DO limitation of 7.0 mg/L (West Yost Associates 2008). The data demonstrate that DO concentrations downstream at R2 are strongly affected by DO concentrations at R1, and for the majority of dates that R2 concentrations were below 7.0 mg/L, there is no evidence that the effluent discharge caused or contributed to the low R2 DO.

As discussed in Section 3.5, the annual migration of adult Cosumnes River fall-run Chinook salmon population occurs in the Lower Cosumnes River during the fall months (October through December, with peak activity typically in November-December). Salmonids are the most intolerant of depressed oxygen levels of any fish species potentially occurring in the Lower Cosumnes River system. However, since Laguna Creek and Skunk Creek lack suitable habitat for spawning, egg incubation, and early rearing, anadromous fishes are unlikely to stray into or remain in these water bodies. Therefore, if DO concentrations were temporarily depressed below 7.0 mg/L in Skunk Creek/Laguna Creek when anadromous salmonids are present in the Lower Cosumnes River, it is not expected to have an adverse effect on these fish or the Cosumnes River’s COLD beneficial use.

With regard to the warmwater fish community of Laguna and Skunk creeks, the EPA has recommended warmwater criteria for DO (EPA 1986) which are more scientifically refined and defensible than those of the Basin Plan (Table 4). Based on a comparison of available DO data for WWTP effluent and Laguna Creek with EPA warmwater criteria, DO concentrations in Laguna Creek are suitable for supporting warmwater fish communities and have rarely fallen below the EPA’s criteria downstream of the WWTP discharge when such a condition did not already exist upstream at R1.

Table 4. EPA-Recommended Ambient Water Quality Criteria for Dissolved Oxygen. Warmwater Criteria (mg/L) Parameter Early Life Stages1 Other Life Stages 30-Day Mean NA 5.5 7-Day Mean 6.0 NA 7-Day Mean Minimum NA 4.0 1-Day Minimum 2,3 5.0 3.0 NA = not applicable 1 Includes all embryonic and larval stages and all juvenile forms to 30 days following hatching. 2 For highly manipulable discharges, further restrictions apply (see pg. 37 of EPA 1986). 3 All minima should be considered as instantaneous concentrations to be achieved at all times.

Specifically, the EPA 30-day mean criterion of 5.5 mg/L was not achieved only one time in April 2007 based on available data; however, at the time the 30-day mean DO concentration at R2 was 5.3 mg/L, concurrent R1 mean 30-day DO concentration was below the criterion and slightly lower than R2 at 5.1 mg/L. The 7-day mean criterion of 6.0 mg/L has not always been achieved;

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 44 IS / Proposed ND

however, it is important to note that: (1) receiving water DO measurements are recorded once on a weekly basis, so they are not necessarily reflective of the actual weekly average, and (2) on only one known occasion (November 15, 2005) was the effluent less than 6.0 mg/L such that it may have contributed to R2 DO concentrations below 6.0 mg/L when R1 concentrations were above the 6.0 mg/L. Based on available data, the EPA’s 1-day minimum criterion of 5.0 mg/L for protection of early life stages, and 7-day minimum criterion of 4.0 mg/L and 1-day minimum criterion of 3.0 mg/L DO for protection of other life stages has always been achieved or if exceeded, it was not caused by the effluent discharge.

Based on the available data collected during the November through April discharge period prior to the recent WWTP upgrades, the receiving water DO conditions downstream of the effluent discharge nearly always meet applicable EPA criteria and effluent may have contributed to DO reduction on only three occasions in 4 years of data assessed (i.e., 97% of sample values were compliant with DO criteria). Moreover, with the recent WWTP upgrades including tertiary filtration and operational changes for improved nitrification, the effluent is anticipated to be characterized by lower BOD concentrations (typically less than 4 mg/L) and lower ammonia concentrations (typically less than 0.7 mg/L N), and potentially improved effluent DO conditions compared to conditions prior to the upgrades. Effluent BOD previously averaged 3.3 mg/L and has been consistently below detection levels (<1.0 mg/L) since January 2011. Ammonia concentrations previously averaged 1.3 mg/L N, but have been below detection levels (<0.2 mg/L-N) following completion of the tertiary filtration and operational changes. The improved effluent quality decreases the potential for incremental receiving water DO reduction, and is anticipated to improve receiving water DO conditions compared to the assessment in the ROWD based on previous data.

Therefore, the effluent discharges under the Proposed Project are not anticipated to result in substantial DO reduction downstream of the discharge point. Any potential reduction in DO concentrations resulting from the discharge during May through October would be expected to be small in magnitude and localized to Skunk Creek and a short distance downstream in Laguna Creek. Any DO reduction would not be expected to extend to the Lower Cosumnes River (i.e., 3 miles downstream of the Galt WWTP discharge location) due to full assimilation of the DO demand within Laguna Creek, available dilution, and subsequent input of DO from re-aeration and photosynthesis as flow moves downstream.

Consequently, a small potential exists for the DO concentrations in Skunk and Laguna creeks to be infrequently below the EPA criteria for protection of warmwater fish under existing conditions. The Proposed Project is not expected to make this current DO condition worse, and in fact, may improve DO conditions due to treatment improvements and reaeration that will occur in relation to the more rapid streamflow downstream of the effluent discharge. Given the infrequent nature in which the criteria are not achieved and the expected improvements in effluent DO concentrations with the recent WWTP upgrades, the proposed May through October effluent discharge would not cause adverse population-level effects on the warmwater communities of Skunk Creek/Laguna Creek. Therefore, based on the available information, the Proposed Project would not result in substantial DO changes in the receiving waters at a frequency, duration, or regional extent to cause adverse effects to beneficial uses downstream of the discharge. Therefore, the potential long-term operations-related DO impacts of the Proposed Project would be less than significant.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 45 IS / Proposed ND

b) Groundwater recharge is dependent on the permeability of soils and amount of recharge that occurs. The Proposed Project does not involve any construction activities, thus there would be no change in the amount of impermeable surfaces in the project area. The City’s termination of the lease with the RCB for agricultural irrigation with recycled water may result in less recharge of the groundwater basin from elimination of irrigation water percolating below the root zone of the crops, assuming the RCB does not acquire a replacement surface water supply or ask the City to continue supplying irrigation water to the site. Moreover, if the RCB decides to irrigate crops via pumping of groundwater, the additional demand and withdrawal of groundwater may reduce groundwater levels. However, irrigation demand associated with the approximately 160 acres of RCB property is negligible relative to the capacity of the underlying aquifers of the region. Thus, the Proposed Project would not affect groundwater recharge conditions, and may negligibly affect groundwater levels indirectly as a result of changes in the irrigation water supply available to the RCB property. Therefore, this impact would be less than significant. c-e) Because the Proposed Project does not involve any construction activity, there would be no change to drainage conditions, onsite or offsite, nor any change in stormwater management features. Moreover, because the project results only in the implementation of effluent discharge operations during the traditionally dry and non-storm event months of May through October, the stormwater runoff conditions for the WWTP would be virtually the same with the Proposed Project as they are under existing conditions. Therefore, there would be no impact. f) The City prepared an antidegradation analysis in August 2009 as a requirement for the renewal of the NPDES permit (RBI 2009). The City’s antidegradation analysis is incorporated herein by reference. The purpose of an antidegradation assessment is to ensure that before an increased rate of wastewater discharge to a receiving water is authorized, sufficient evidence exists to show that existing beneficial uses of the water will be protected, and that any degradation of water quality will be limited and consistent with state and federal antidegradation policies. The antidegradation analysis evaluated the proposed project and associated potential for effluent discharge during the months of May through October to increase concentrations of regulated and unregulated constituents in downstream receiving waters, and thereby to reduce the remaining available assimilative capacity for contaminant inputs. Assimilative capacity is the difference between the concentration of a constituent in a receiving water and an applicable water quality objective/criterion for the constituent, and is a measure of the ability of a water body to accept additional constituent input before concentrations exceed the objective/criterion. The antidegradation analysis evaluated potential changes in constituent concentrations and assimilative capacity in the receiving water at the Proposed Project discharge rate of 3.0 MGD. For the purposes of this assessment of the potential for project operations to exceed the threshold of significance, the term “substantially degrade” is defined as a change that would cause long‐term degradation of existing water quality that would cause substantial adverse effects to one or more beneficial uses of a water body.

The degradation in receiving-water quality that may occur as a result of the Proposed Project would be expected to result in limited water quality changes (RBI 2009). The predicted lowering of water quality is anticipated to not involve long-term exceedances of applicable regulatory criteria/objectives for any constituents. As noted in the discussion for checklist question (b) above, the City is implementing groundwater well head treatment systems to reduce arsenic concentrations in the water supply and the effluent. Additionally, the reduced assimilative capacity for nitrate is

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 46 IS / Proposed ND

temporary and would increase in the future based on projected growth in the City and the need to expand the WWTP capacity. At that time, the City will implement denitrification processes to further reduce nitrogen discharge concentrations. For all constituents assessed, the receiving water would retain a large amount of the available assimilative capacity for any other future constituent loading from unforeseen sources. Thus, the potential protection of beneficial uses in the future would not be substantially reduced. Overall, as presented in the City’s detailed antidegradation analysis (RBI 2009), while resulting in limited degradation of water quality for some constituents in Laguna Creek, the Proposed Project accommodates important socioeconomic development in the service area while maintaining full protection of the beneficial uses of the receiving water bodies. The Regional Water Board, in adopting the renewed NPDES permit, has determined that the limited degradation that would occur as a result of the discharge and the specific constituents is consistent with the state and federal antidegradation policies, and would not cause substantial risk of adverse effects on beneficial uses. Thus, this impact is considered less than significant.

g-j) Because the Proposed Project does not involve any construction activity, there would be no change to floodplains or exposure to flooding conditions or seiche/tsunami/mudflow hazards. Consequently, there would be no impact.

3.11 Stormwater Quality

Less than Potentially Less than Significant Would the project: Significant Significant No Impact with Impact Impact Mitigation a) Result in increase of erosion during the construction process? b) Result in an increase of the level of pollutants in storm water runoff from the post-construction activities? c) Result in an increase of the discharge of storm water from material storage areas, vehicle or equipment fueling, vehicle or equipment maintenance (including washing), waste handling, hazardous materials handling or storage, delivery areas or loading docks, or other outdoor work areas? d) Cause the impairment of the beneficial uses of receiving waters or areas that provide water quality benefit or cause significant harm on the biological integrity of the waterways and water bodies by the discharge of storm water? e) Cause significant changes in the flow velocity or volume of storm water runoff to cause environmental harm and the potential for significant increases in erosion of the project site and surrounding areas?

3.11.1 Setting

Stormwater facilities at the existing WWTP site drain to the existing treated effluent storage reservoir, thus contributing to the effluent discharge to Skunk Creek. Stormwater is generated during winter rainfall events, which in the project area, primarily occur during the months of November through April.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 47 IS / Proposed ND

3.11.2 Discussion a-e) The Proposed Project does not involve any construction or change in operations that would change the quantity or quality of stormwater runoff that is generated at the WWTP or discharged to receiving water during the typical months of seasonal storm events (i.e., November through April). Moreover, the Proposed Project involves a change in the discharge of effluent only during the months of May through October. Thus, the May through October effluent discharge would not contribute to runoff-related erosion or water quality effects. Therefore, there would be no impact.

3.12 Land Use and Planning

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Physically divide an established community? b) Conflict with any applicable land use plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to the general plan, specific plan, local coastal program, or zoning ordinance) adopted for the purpose of avoiding or mitigating an environmental effect? c) Conflict with any applicable habitat conservation plan or natural community conservation plan?

3.12.1 Setting

The City of Galt’s General Plan designates the project area as public/quasi-public (City of Galt 2008b). The public/quasi-public land use designation applies to, in addition to the WWTP, parks, institutional facilities such as schools, and police and fire stations (City of Galt 2008b).

3.12.2 Discussion a-c) The Proposed Project does not involve any construction or change in operations that would change existing land uses. Thus, no existing communities would be physically divided by the Proposed Project and there would be no conflict with the existing land use designations. As described in Section 3.5, Biological Resources, the project area does not lie within the boundaries of an adopted habitat conservation plan or natural community conservation plan. Therefore, there would be no impact.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 48 IS / Proposed ND

3.13 Mineral Resources

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Result in the loss of availability of a known mineral resource that would be of value to the region and the residents of the state? b) Result in the loss of availability of a locally-important mineral resource recovery site delineated on a local general plan, specific plan or other land use plan?

3.13.1 Setting

The project area does not contain any state- or local-designated mineral resources (City of Galt 2008b).

3.13.2 Discussion a-b) Because the project area does not contain any state- or local-designated mineral resources, the Proposed Project would not affect these resources. Therefore, there would be no impact.

3.14 Noise

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Exposure of persons to or generation of noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? b) Exposure of persons to or generation of excessive groundborne vibration or groundborne noise levels? c) A substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project? d) A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project? e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels? f) For a project within the vicinity of a private airstrip, would the project expose people residing or working in the project area to excessive noise levels?

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 49 IS / Proposed ND

3.14.1 Setting

Noise levels in California are typically measured in dBA, which is the A-weighted sound level of decibels (dB). This scale gives greater weight to the frequencies of sound to which the human ear is most sensitive. Decibels are a unit of measurement indicating the relative amplitude or intensity of a sound. The intensity of a sound and the subjective noisiness or loudness is related as is the intensity of a sound and a sensitive receptor’s distance to that sound. Sensitive noise receptors are typically residential land uses. The closest noise-sensitive receptors outside the boundaries of the facility are single family residences located south of Twin Cities Road, approximately 1,800 feet to the south of the project site.

3.14.2 Discussion a-f) The Proposed Project does not involve any construction or change in operations that would change noise generation sources in the project area or exposure of receptors to noise from the WWTP. Therefore, no effects on noise are anticipated as a result of implementing the Proposed Project. Therefore, there would be no impact.

3.15 Population and Housing

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Induce substantial population growth in an area, either directly (for example, by proposing new homes and businesses) or indirectly (for example, through extension of roads or other infrastructure)? b) Displace substantial numbers of existing housing, necessitating the construction of replacement housing elsewhere? c) Displace substantial numbers of people, necessitating the construction of replacement housing elsewhere?

3.15.1 Setting

The City of Galt’s estimated population in 2011 was about 24,000, which makes it the second smallest city in Sacramento County (California Department of Finance 2011). No houses are located within the project area. The nearest houses are located on Twin Cities Road, approximately 1,800 feet from the WWTP.

3.15.2 Discussion a-c) The Proposed Project does not involve any construction activity or change in the wastewater treatment and effluent disposal capacity of the WWTP. Therefore, no effects on population or housing are anticipated as a result of implementing the Proposed Project. Therefore, there would be no impact.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 50 IS / Proposed ND

3.16 Public Services

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Would the project result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, need for new or physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times or other performance objectives for any of the public services:

i) Fire protection?

ii) Police protection?

iii) Schools?

iv) Parks?

v) Other public facilities?

3.16.1 Setting

Fire protection for the City of Galt, the City of Elk Grove, and some outlying areas of Sacramento County is provided by the Cosumnes Community Services District (CCSD) Fire Department. The City maintains a police force, with headquarters located approximately 2 miles from the WWTP. The closest school to the project area is the Lake Canyon Elementary School, which is located approximately 0.9 miles southeast of the project area.

3.16.2 Discussion a) The Proposed Project does not involve any construction activity or change in the wastewater treatment and effluent disposal capacity of the WWTP. Thus, the Proposed Project would not increase the need for public services. Therefore, there would be no impact.

3.17 Recreation

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Would the project increase the use of existing neighborhood and regional parks or other recreational facilities such that substantial physical deterioration of the facility would occur or be accelerated? b) Does the project include recreational facilities or require the construction or expansion of recreational facilities which might have an adverse physical effect on the environment?

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 51 IS / Proposed ND

3.17.1 Setting

No recreational facilities or activities are located within the existing WWTP facility, including the project area. A private gun range, used by the City’s police department and other approved law enforcement agencies, is within the boundaries of the WWTP property in the northwest corner of the site.

3.17.2 Discussion a-b) The project does not involve any construction or change in operations that would result in any change to the existing gun range within the WWTP boundaries. The Proposed Project does not involve any change in the WWTP capacity that would lead to additional growth, thus there would be no change in the use of existing recreational facilities or expansion of any recreational facilities. Therefore, there would be no impact.

3.18 Transportation/Traffic

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Exceed the capacity of the existing circulation system, based on an applicable measure of effectiveness (as designated in a general plan policy, ordinance, etc.), taking into account all relevant components of the circulation system, including but not limited to intersections, streets, highways and freeways, pedestrian and bicycle paths, and mass transit? b) Conflict with an applicable congestion management program, including, but not limited to level of service standards and travel demand measures, or other standards established by the county congestion management agency for designated roads or highways? c) Result in a change in air traffic patterns, including either an increase in traffic levels or a change in location that results in substantial safety risks? d) Substantially increase hazards due to a design feature (e.g., sharp curves or dangerous intersections) or incompatible uses (e.g., farm equipment)? e) Result in inadequate emergency access? f) Conflict with applicable adopted policies, plans, or programs supporting alternative transportation (e.g., bus turnouts, bicycle racks)?

3.18.1 Setting

The WWTP is primarily accessed from Twin Cities Road, west of Highway 99, a four-lane north-south freeway. Twin Cities Road (also known as State Route 104) on the east side of

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 52 IS / Proposed ND

Highway 99 runs east-west and is the major arterial in the project vicinity. Twin Cities Road is a two-lane road that connects Galt to Interstate 5 to the west and into Amador County.

3.18.2 Discussion a-f) The Proposed Project does not involve any construction activity or change in the wastewater treatment and effluent disposal operations that would result in any changes to existing transportation facilities or traffic. Thus, there would be no impact.

3.19 Utilities and Service Systems

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Exceed wastewater treatment requirements of the applicable Regional Water Quality Control Board? b) Require or result in the construction of new water or wastewater treatment facilities or expansion of existing facilities, the construction of which could cause significant environmental effects? c) Require or result in the construction of new storm water drainage facilities or expansion of existing facilities, the construction of which could cause significant environmental effects? d) Have sufficient water supplies available to serve the project from existing entitlements and resources, or are new or expanded entitlements needed? e) Result in a determination by the wastewater treatment provider which serves or may serve the project that it has adequate capacity to serve the project’s projected demand in addition to the providers existing commitments? f) Be served by a landfill with sufficient permitted capacity to accommodate the project's solid waste disposal needs? g) Comply with federal, state, and local statutes and regulations related to solid waste?

3.19.1 Setting

The sanitary sewer collection and treatment system are operated by the City’s Public Works Department. The City’s WWTP, which includes the project area, meets all wastewater treatment needs of the approximately 6,056 sewer service accounts in the City (City of Galt 2005). The current treatment capacity and permit allowances are expected to meet the needs of the City through buildout of the 2008 city limits. This project will not affect the existing, approved capacity of the WWTP.

The City’s Public Works Department operates the potable water supply and distribution system in Galt. All water demands are met through groundwater supplies. Stormwater on the project

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 53 IS / Proposed ND

area is captured and collected by an existing stormwater drainage system. The City contracts to a commercial operator for collection and disposal of solid waste generated in the City.

3.19.2 Discussion a-g) The Proposed Project does not involve any construction activity or change in the wastewater treatment and effluent disposal capacity of the WWTP. Thus, the Proposed Project would not increase the need for public services. Therefore, there would be no impact.

3.20 Mandatory Findings of Significance

Less than Potentially Less than Significant Would the project… Significant Significant No Impact with Impact Impact Mitigation a) Does the project have the potential to degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal community, reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory? b) Does the project have impacts that are individually limited, but cumulatively considerable? (“Cumulatively considerable” means that the incremental effects of a project are considerable when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects)? c) Does the project have environmental effects that will cause substantial adverse effects on human beings, either directly or indirectly?

The environmental analysis above indicates that the Proposed Project has the potential to adversely affect Biological Resources and Hydrology and Water Quality. Additional discussion regarding these resource topics is presented below.

3.20.1 Discussion a) As discussed in Section 3.5, Biological Resources, the Proposed Project could affect fall run Chinook salmon as a result of the effluent discharge into Skunk Creek which may contribute to streamflow continuity in Laguna Creek and the Lower Cosumnes River to the area of tidal influence. Surface streamflow continuity in the late fall at the beginning of the adult salmon migration season may result in attracting adults to stray into Laguna Creek when they otherwise might have reduced passage opportunity under existing conditions. However, as described in Section 3.5, this potential impact is considered less than significant.

As discussed in Section 3.10, Hydrology and Water Quality, the Proposed Project would result in discharge of treated wastewater effluent to Skunk Creek/Laguna Creek during the additional period

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 54 IS / Proposed ND

of May through October. The discharge-related effects would result in compliance with all applicable water quality standards for constituents of concern in the receiving water. Thus, the discharge would not adversely affect any beneficial uses in Skunk Creek, Laguna Creek, Lower Cosumnes River, or water bodies further downstream of the discharge.

Therefore, the project does not have the potential to degrade the quality of the environment, substantially reduce the habitat of a species, cause the population to drop below self-sustaining levels, threaten to eliminate a community, or reduce the number or restrict the range of the species. This impact is less than significant.

b) The initial study identifies impacts related to biological resources (fisheries) and water quality that may contribute to future cumulative impacts. Past, present, and reasonably foreseeable activities occurring in the project area, including agriculture, construction, and population growth may adversely affect aquatic biological resources and water quality under future cumulative conditions. With the anticipated growth in the City’s population in the future, the City would expand WWTP capacity to accommodate growth which would result in increased effluent discharge to Skunk Creek. Potential changes may occur in general ecosystem functions, aquatic habitat, hydrology, water temperature, and water quality under future conditions that may have substantial adverse effects on fall-run Chinook salmon. In particular, the current conditions for anadromous fish species in the Delta and many upper watershed areas are considered impaired with respect to direct entrainment loss of fish in water diversions, predation, loss and alteration of habitat, Delta flow- related effects to migration of anadromous fish species, and the effects of invasive species. Numerous fisheries management plans and restoration programs, including the Central Valley Project Improvement Act, Anadromous Fish Restoration Program, Ecosystem Restoration Program Plan of the CALFED Bay-Delta Program, and current Bay-Delta Conservation Plan efforts have been initiated, in part, to offset the adverse ecological effects imposed on the Delta and upstream watersheds and its fisheries resources associated with increased growth and development. While a key objective of the numerous resource management programs is to facilitate improved conditions for fisheries resources, the future cumulative condition for fall-run Chinook salmon is considered significant, primarily due to uncertainty regarding overall future Delta ecosystem conditions and the level of recovery that may occur in the Delta and upper watersheds as a result of restoration and conservation efforts.

The effluent discharge-related flow contribution to Laguna Creek and the Lower Cosumnes River could contribute to continuity of surface water flow from Laguna Creek to the tidally influenced reach of the Lower Cosumnes River. Surface flow is a factor that can facilitate straying of adult fall-run Chinook salmon from their natal stream into a non-natal stream such as Laguna Creek. However, the Proposed Project is not anticipated to change the potential for fall-run Chinook salmon to stray from the Lower Cosumnes River because the additional flow would not substantially change existing flow conditions. In particular, project-related flow changes would be small during October when adult fall-run Chinook first arrive and begin holding in the Lower Cosumnes River prior to the typical migration period. The presence of municipal wastewater in the flow also may detract straying because salmon generally avoid the change in water quality conditions associated with constituents in wastewater. Consequently, the Proposed Project would not result in a considerable contribution to any significant future cumulative adverse conditions for fall-run Chinook salmon or other fish species.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 55 IS / Proposed ND

Future cumulative water quality conditions in the Laguna Creek and Cosumnes River watersheds are not anticipated to be substantially different than the current conditions. Primarily forested lands occupy the upper Cosumnes River watershed, and lands within the lower Central Valley portion of the watersheds are rural, largely consisting of managed agricultural lands (e.g., crops, grazing, orchards). Land uses in the Laguna Creek and Cosumnes River watersheds, which are key determining factors in base streamflow quality and runoff, are not anticipated to substantially change in the future. Consequently, the future streamflow quality in the region can reasonably be expected to remain similar to existing conditions. As noted in Section 3.10, Laguna Creek is not identified on the state’s Section 303(d) list of water quality impaired water bodies, and the Cosumnes River is Section 303(d) listed for impairment by E. coli bacteria, sediment toxicity, and invasive species. Total Maximum Daily Load (TMDL) programs have not been prepared yet to address the Section 303(d) constituents, but are expected to be developed by the Central Valley Regional Water Board in the future. A TMDL is developed to identify the major source loads of these constituents and define a course of implementation actions to improve the water quality and resolve the Section 303(d) compliance issues. The City’s WWTP provides highly treated and disinfected wastewater, and thus is a negligible source (if at all) of the constituents at issue for the Section 303(d) listings in the Cosumnes River. Thus, the future water quality conditions in the project area will be influenced primarily by existing natural runoff, Rancho Seco irrigation water deliveries, and the City’s year-round effluent discharge, including potential expanded WWTP capacity flows in response to population growth. Based on this water quality assessment of the Proposed Project, the future cumulative water quality conditions in the project area (i.e., Skunk Creek, Laguna Creek, and Lower Cosumnes River) are not anticipated to substantially exceed applicable criteria at a frequency or duration, or cause substantial long-term degradation, such that beneficial uses would be adversely affected. Thus, the Proposed Project would not contribute considerably to any significant impact. c) The Proposed Project involves only a change in the City’s WWTP effluent disposal operations, consisting of the addition of effluent discharge to Skunk Creek during May through October, and potentially reduced reclamation irrigation operations through possible elimination of agricultural irrigation of RCB property. No construction activities are involved, and there would be no changes in facility capacity, functions, or operations of any other WWTP component. Therefore, the project does not have environmental effects that will cause substantial adverse effects on human beings, either directly or indirectly.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 56 IS / Proposed ND

4 REFERENCES

4.1 Printed References

Barnes, K.K., D.W. Koplin, M.T. Meyer, E.M. Thurman, E.T. Furlong, S.D. Zuagg, and L.B. Barber. 2002. Water-Quality Data for Pharmaceuticals, Hormones, and Other Organic Wastewater Contaminants in U.S. Streams, 1999–2000. U.S. Geological Survey Open File Report 02-94. California Department of Conservation. 1999. California Geological Survey - Alquist-Priolo Earthquake Fault Zones, Table 4. Cities and Counties Affected by Alquist-Priolo Earthquake Fault Zones as of May 1, 1999. A vailable: < http://www.conservation.ca.gov/cgs/rghm/ap/Pages/affected.aspx >. Accessed: March 9, 2009. Last posted or revised: 2007.

California Department of Finance. 2011. E-1 City/County/State Population Estimates with Percent Change, January 1, 2010 - 2011. Sacramento, California, May 2008. Available: < http:// www.dof.ca.gov/research/demographic/reports/estimates/e-1/view.php >. Accessed: June 2011. Last posted or revised: January 2011.

California Department of Fish and Game (CDFG). 2011. GrandTab, California Central Valley, Sacramento and San Joaquin River Systems, Chinook Salmon Escapement, Hatcheries and Natural Areas. February. Available at: http://www.calfish.org/tabid/104/Default.aspx

———. 2009. California Natural Diversity Data Base (CNDDB). Sacramento, CA. Electronic database. Accessed April 2009.

California Department of Toxic Substances Control (DTSC). 2007. Defining Hazardous Waste. Available: < http://www.dtsc.ca.gov/HazardousWaste/index.cfm#Hazardous_ Waste Identification>. Accessed: March 18, 2009. Last posted or revised: February 9, 2007.

California Department of Water Resources (DWR). 2006. Bulletin 118- Individual Basin Description for the Cosumnes Subbasin, 5-22.16. Available at: < http://www.groundwater.water.ca.gov/bulletin118/basin_desc/basins_s.cfm#gwb39htm >. Last posted or revised: January 20, 2006. Accessed: April 29, 2009.

Carollo Engineers. 2011a. City of Galt Wastewater Treatment Plant and Reclamation Facility Ammonia Compliance Work Plan and Schedule. (March). Sacramento, CA

———. 2011b. City of Galt Wastewater Treatment Plant and Reclamation Facility, NPDES Permit Compliance Studies, Compliance Work Plan and Schedule for TSO Constituents. (March). Sacramento, CA

Central Valley Regional Water Quality Control Board (Regional Water Board). 2009. Water Quality Control Plan (Basin Plan) for the Sacramento and San Joaquin River Basins. Available: < http://www.waterboards.ca.gov/centralvalley/water_issues/basin_plans/ >. Last posted or revised: September 2009.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 57 IS / Proposed ND

City of Galt. 2011. City of Galt Annual 2030 Galt General Plan and Housing Element Progress Report: 2010. (March). Available: < http:// www.ci.galt.ca.us/index.aspx?page=472 >. Accessed: June 17, 2011.

———. 2008a. Initial Study/Proposed Mitigated Negative Declaration. City of Galt Wastewater Treatment Plant Effluent Pipeline Project. October 2008.

———. 2008b. General Plan Policy Document Public Review Draft. Available: < http:// www.ci.galt.ca.us/index.aspx?page=472 >. Accessed: June 17, 2011.

———. 2005. City of Galt General Plan Existing Conditions Report for the 2008 General Plan. Prepared by Mintier & Associates, et al. November. Available: < http:// www.ci.galt.ca.us/index.aspx?page=472 >. Accessed: June 17, 2011.

Desbrow, C., E.J. Routledge, G.C. Brighty, J.P. Sumpter, and M. Waldock. 1998. Identification of Estrogenic Chemicals in STW Effluent. 1. Chemical Fractionation and in Vitro Biological Screening. Environ, Sci. Technol. 32 (11), 1549-1558.

Dittman, A.H., T.P. Quinn, and G.A. Nevitt. 1996. Timing of imprinting to natural and artificial odors by coho salmon (Oncorhynchus kisutch). Can. J. Fish. Aquat. Sci. 53:434–442.

El Dorado Irrigation District. 2008. Waste Discharge Requirements for the El Dorado Irrigation District Deer Creek Wastewater Treatment Plant (Order No. R5-2008-0173, NPDES No. CA0078662).

Environmental Protection Agency (EPA). 2009. EnviroMapper. Available: < http://www.epa.gov/enviro/html/em/ >. Accessed: April 30, 2009. Last posted or revised: April 10, 2009. Washington, D.C.

———. 1986. Quality Criteria for Water 1986. Office of Water. EPA 440/5-86-001. Washington, D.C.

Hall, J.C., W.T. Hall, and C.T. Simmons. 1997. Water quality criteria for copper: A need for revisions to the national standard. Water Environment and Technology 9:45-49. Hasler, A.D., A.T. Scholz, and A.M. Horrall. 1978. Olfactory imprinting and homing in salmon. Am. Sci. 66:347-355.

Jobling, S., M. Nolan, C.R. Tyler, G. Brighty, and J.P. Sumpter. 1998. Widespread Sexual Disruption in Wild Fish. Environmental Science and Toxicology. 32:2498–2506.

Miège, C., J.M. Choubert, L. Ribeiro, M. Eusèbe, and M. Coquery. 2009. Fate of pharmaceuticals and personal care products in wastewater treatment plants - Conception of a database and first results. Env. Poll. 157 (2009): 1721-1726.

Mount, J., G.E. Fogg, L. Kavaas, J. Fleckenstein, M. Anderson, Z.Q. Chen, and E. Suzuki. 2001. Linked Surface Water-Groundwater Model for the Cosumnes River Watershed: Hydrologic Evaluation of Management Options to Restore Fall Flows. Sponsor: U.S. Fish and Wildlife Service Anadromous Fish Restoration Program Cooperative

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 58 IS / Proposed ND

Agreement No. 11332-8-J264. (September). Available at: < http://watershed.ucdavis.edu/pdf/Mount-et-alUSFWS-2007.pdf > Accessed May 2011.

Natural Resources Conservation Service (NRCS). 2009. United States Department of Agriculture Web Soil Survey. Available: < http://websoilsurvey.nrcs.usda.gov/ >. Accessed April 2009.

Pascual, M.A., and T.P. Quinn. 1994. Evaluations of alternative models of the coastal migrations of adult Fraser River sockeye salmon (Oncorhynchus nerka). Can. J. Fish. Aquat. Sci. 48:799-810.

Quinn, T.P. 2005. The behavior and ecology of Pacific salmon and trout, 1st edition. American Fisheries Society, Bethesda, Maryland in association with University of Washington Press, Seattle and London.

Quinn, T.P., and K. Fresh. 1984. Homing and straying in chinook salmon (Oncorhynchus tshawytscha) from Cowlitz River Hatchery, Washington. Can. J. Fish. Aquat. Sci. 41:1078-1082.

Quinn, T.P., R.S. Nemeth, and D.O. McIsaac. 1991. Patterns of homing and straying by fall Chinook salmon in the lower Columbia River. Trans. Am. Fish. Soc. 120:150-156.

Oppenheimer, J., and R. Stephenson. 2006. Characterizing the passage of personal care products through wastewater treatment processes. Water Env. & Tech. 18(12): 1521- 1542.

Robertson-Bryan, Inc. (RBI). 2009. Antidegradation Analysis for the City of Galt Wastewater Treatment Plant Expansion Project. Prepared for the Central Valley Regional Water Quality Control Board on behalf of the City of Galt. (August).

Schroeder, R.K., R.B. Lindsay, and K.R. Kenaston. 2001. Origin and straying of hatchery winter steelhead in Oregon coastal rivers. Trans. Am. Fish. Soc. 130:431–441.

Smith, E.H., and H.C. Bailey. 1990. Preference/avoidance testing of waste discharges on anadromous fish. Env. Tox. Chem. 9:77-86.

State Water Resources Control Board (SWRCB). 2010. 2010 Integrated Report (Clean Water Act Section 303(d) List / 305(b) Report. Available: . Accessed: May 2011.

———. 2007. 2006 CWA Section 303(d) List of Water Quality Limited Segments. Approved by U.S. EPA. Available:

U.S. Fish and Wildlife Service (USFWS). 2011. Species list. Available: < http://www.fws.gov/sacramento/es/spp_list.htm >. Accessed: May 2011.

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 59 IS / Proposed ND

———. 2009b. National Wetlands Inventory. Available: < http://www.fws.gov/nwi/ >. Accessed: April 2009.

Western Regional Climate Center. 2005. Period of Record Monthly Climate Summary Lodi, California (045032). Period of Record 7/1/1948 to 12/31/2005. Available: < http://www.wrcc.dri.edu/summary/climsmnca.html >. Last posted or revised: 2005. Accessed: April 30, 2009.

West Yost Associates. 2009. Technical Memorandum: Control of Effluent Ammonia at the Galt WWTP. Prepared for Robertson-Bryan, Inc. June 6.

———. 2008. City of Galt Wastewater Treatment Plant, Report of Waste Discharge and NPDES Permit Application.

World Health Organization. 2002. Global Assessment of the State-of-the-Science of Endocrine Disruptors. International Programme on Chemical Safety. Rome.

4.2 Personal Communications

Dahlberg, Bo. City of Galt Wastewater Treatment Plant Supervisor. April 26, 2011 – phone conversation with Jeff Lafer (Robertson-Bryan, Inc.) regarding reclamation irrigation operations and records of fall-run Chinook salmon in Laguna Creek.

Kennedy, Trevor. Fisheries Foundation of California. June 14, 2011 – phone conversation with Michael Bryan (Robertson-Bryan, Inc.) regarding Cosumnes River fall-run Chinook salmon conditions.

5 LIST OF PREPARERS

Robertson-Bryan, Inc.

ƒ Michael Bryan, Ph.D., Principal-in-Charge ƒ Michelle Brown, P.E., Senior Water Resources Engineer ƒ Jeff Lafer, Project Manager, Hydrology and Water Quality Specialist ƒ David Thomas, Project Biologist ƒ Joan McHale, Staff Scientist/Editor

WWTP Summer Surface Water Discharge Project Robertson-Bryan, Inc. City of Galt 60 IS / Proposed ND

Appendix A

Hydrologic Analysis of City of Galt Summer Surface Water Discharge Project

HYDROLOGIC AND HYDRAULIC ANALYSIS OF LAGUNA CREEK AND LOWER COSUMNES RIVER

Prepared for:

CITY OF GALT

Prepared by:

June 2011

HYDROLOGIC AND HYDRAULIC ANALYSIS OF LAGUNA CREEK AND LOWER COSUMNES RIVER

Prepared for:

CITY OF GALT 495 Industrial Drive Galt, CA 95632-2039

Prepared by:

9888 Kent Street Elk Grove CA 95624 (916) 714-1801

June 2011

TABLE OF CONTENTS

SECTION PAGE

EXECUTIVE SUMMARY ...... 1

1 INTRODUCTION ...... 2

2 LAGUNA CREEK ...... 3

2.1 WATERSHED ...... 3 2.2 FLOWS ...... 3 3 MODEL DEVELOPMENT ...... 5

3.1 GEOMETRY DATA ...... 5 3.2 EVAPOTRANSPIRATION ...... 7 3.3 SEEPAGE ...... 7 3.4 ADDITIONAL DOWNSTREAM DIVERSION ...... 7 4 ANALYSIS ...... 8

4.1 EXISTING CONDITIONS...... 8 4.2 PROJECT CONDITIONS...... 9 5 CONCLUSION ...... 10

6 REFERENCES ...... 11

LIST OF TABLES

Table 1. Estimated Average Daily Flows (cfs) in Laguna Creek after Galt Irrigation District Water Usage. 3 Table 2. Monthly Minimum, Average, and Maximum Evapotranspiration (in/day) at Lodi from 2001 to 2010...... 7 Table 3. Estimated Monthly Diversion (cfs) from Laguna Creek below Twin Cities Road...... 8 Table 4. Flows (cfs) in Laguna Creek Upstream of the Discharge Point (Inflow), Lower Cosumnes River just Upstream of the Tidal Influence Area (Outflow) and the Corresponding Depth (ft) under Existing Conditions for Wetness Categories...... 9 Table 5. Estimated monthly discharge from the WWTP...... 9 Table 6. Project Flows (cfs) in Laguna Creek at the Discharge Point, including WWTP Discharge (Inflow), Flows in the Lower Cosumnes River just Upstream of the Tidal Influence Area (Outflow), the Corresponding Depth (ft) and the Change in Depths (Diff) at the Tidal Influence Area under the Project Conditions for Wetness Categories...... 10

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant i Hydrologic and Hydraulic Analysis TABLE OF CONTENTS

SECTION PAGE

LIST OF FIGURES

Figure 1. Laguna Creek Watershed...... 4 Figure 2. Example of Laguna Creek Cross-Section...... 6 Figure 3. Example of Lower Cosumnes River Cross-Section...... 6

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant ii Hydrologic and Hydraulic Analysis

EXECUTIVE SUMMARY

Robertson-Bryan, Inc. (RBI) performed hydrologic and hydraulic analysis of Laguna Creek and Lower Cosumnes River to evaluate the City of Galt’s proposed initiation of effluent discharges during the May through October period of the year (Proposed Project). The RBI effort included estimation of Laguna Creek flows under existing conditions, estimation of evapotranspiration and seepage losses, extraction of geometry data, hydrologic analysis with the U.S. Army Corps of Engineer’s Hydrologic Engineering Centers River Analysis System (HEC-RAS) model, and evaluation of the flow regime in Laguna Creek and Lower Cosumnes River under existing and Project conditions.

Based on the hydrologic and hydraulic analysis, RBI estimates that surface flow continuity exists in the Lower Cosumnes River from its confluence with Laguna Creek to the area of tidal influence in September and October with existing conditions. The addition of the City’s proposed effluent would increase the water depths slightly (0.20 ft – 0.32 ft) throughout this reach of the Lower Cosumnes River, relative to existing conditions.

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant 1 Hydrologic and Hydraulic Analysis

1 INTRODUCTION

The Central Valley Regional Water Quality Control Board (Regional Water Board) renewed the City of Galt’s (City) National Pollutant Discharge Elimination System (NPDES) permit and Waste Discharge Requirements (WDRs) for operating the Waste Water Treatment Plant (WWTP) in September 2010. The renewed NPDES permit authorizes surface water discharge of the effluent to Skunk Creek during the May 1–October 31 period (Proposed Project) following implementation of effluent quality improvements at the WWTP.

From November 1 through April 31, WWTP effluent disposal currently consists of a combination of surface water discharge to Skunk Creek and reclamation reuse (i.e., irrigation) on approximately 174 acres of City-owned land and on 160 acres of land owned by the Roman Catholic Church. Under the former NPDES permit, effluent disposal during May 1 through October 31, occurred entirely through reclamation irrigation, pursuant to a seasonal discharge prohibition.

The City completed construction of treatment upgrades to the WWTP in January 2011, which includes new tertiary filtration, ultraviolet light (UV) disinfection, and biosolids handling facilities. The WWTP upgrades were necessary to meet more stringent water quality effluent limitations that were specified in the renewed NPDES permit. In doing so, the effluent quality improvements are now sufficient to allow year-round surface water discharge.

The City was unable to secure additional land for reclamation irrigation that would be necessary to accommodate expected future increased wastewater flows. Moreover, the City was unable to secure long-term reclaimed water delivery to existing private delivery sites. Accordingly, given the WWTP upgrades are now operational, thereby achieving the permit-required effluent quality performance suitable for discharge, the City will likely implement May through October surface water discharge. The discharge of effluent during the May through October period could be up to a rate of 3.0 million gallons per day (MGD, 4.55 cfs), which is the current design capacity of the WWTP.

Robertson-Bryan, Inc. (RBI) performed hydrologic and hydraulic analysis of Laguna Creek and Lower Cosumnes River to evaluate the City of Galt’s proposed initiation of effluent discharges during the May through October period of the year. The RBI effort included estimation of Laguna Creek flows under existing conditions, estimation of evapotranspiration and seepage losses, extraction of geometry data, development of HEC-RAS model, and evaluation of the flow regime in Laguna Creek and Lower Cosumnes River under existing and Project conditions.

This report describes the hydrologic and hydraulic analysis performed to estimate the flow regime in Lower Cosumnes River at the tidal influence area

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant 2 Hydrologic and Hydraulic Analysis

2 LAGUNA CREEK

2.1 WATERSHED

Laguna Creek is approximately 50 miles long and drains approximately 185 square miles (Figure 1). The Laguna Creek watershed begins at about 15 feet above mean sea level (msl) at the creek’s confluence with the Cosumnes River, and extends to around 900 feet msl at the top of the watershed. Agriculture and grazing land uses dominate the Laguna Creek watershed.

2.2 FLOWS

Flow in Laguna Creek is seasonal, with little or no natural flow outside the precipitation season (October–April). Sacramento Municipal Utility District (SMUD) supplements Laguna Creek flows by year-round discharges sold to Galt Irrigation District (GID) from the Rancho Seco facility – about 16 cubic feet per second (cfs) into Hadselville Creek. Hadselville Creek joins Laguna Creek just upstream of the Folsom South Canal.

During the winter months, the natural flow, plus the discharge from Rancho Seco, generally flows unimpaired to the Cosumnes River. During the summer and fall, farmers in the Galt Irrigation District use the water from Laguna Creek for irrigation. As no stream gauges are currently available on Laguna Creek, the flow in Laguna Creek downstream of Highway 99 is estimated as the resultant flow of Rancho Seco discharge after GID usage. Table 1 below also shows the estimated average daily flows (cubic feet per second-cfs) in Laguna Creek after GID water usage.

Table 1. Estimated Average Daily Flows (cfs) in Laguna Creek after Galt Irrigation District Water Usage. Month 2002 2003 2004 2005 2006 2007 2008 2009 April 11.5 10.5 10.2 18.2 24.3 14.4 10.3 10.9 May 7.5 9.8 0.0 19.9 14.8 5.1 4.3 9.3 June 5.3 4.5 5.1 17.2 8.1 0.0 4.0 2.3 July 1.6 3.6 4.6 0.0 3.1 5.4 0.0 0.0 August 6.1 6.7 2.6 8.2 9.5 10.8 0.0 0.0 September 8.9 7.7 4.2 9.0 10.5 9.5 7.3 5.3 October 14.6 13.7 12.3 16.3 14.2 11.8 13.5 16.1 While treated as a static system, GID has, and will likely increase its utilization of Rancho Seco discharge thus tending to decrease base case flows as listed in Table 1.

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant 3 Hydrologic and Hydraulic Analysis

Figure 1. Laguna Creek Watershed.

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant 4 Hydrologic and Hydraulic Analysis Report

3 MODEL DEVELOPMENT

The United States Army Corps of Engineers developed River Analysis System (HEC-RAS) to perform one-dimensional steady and unsteady flow river hydraulics calculations. RBI used this software to perform a steady-state analysis of Laguna Creek and Cosumnes River conditions during May through October. Model includes approximately three miles of Laguna Creek and two miles of Cosumnes River.

3.1 GEOMETRY DATA

RBI extracted five cross-sections for three miles of Laguna Creek and four cross-sections for the two miles of the Lower Cosumnes River channel from Light Detection And Ranging (LiDAR) data developed by University of California, Davis. These nine cross-sections were interpolated to create an additional 11 cross-sections for detailed analysis. Figure 2 and 3 below show an example of Laguna Creek and Lower Cosumnes River cross-section.

Using this geometry data, RBI developed and executed the HECRAS model with flows from 0 to 25 cfs with 0.1 cfs increments. Water Surface Elevation, Flow Area, Top Width, and Wetted Perimeter for these cross-sections were extracted from the model to create a Microsoft Excel model to analyze the flow regime based on water year type.

Based on Sacramento Valley Index, there were one Wet year, one Above Normal year, two Below Normal years, three Dry years and one critically dry year between 2002 and 2009. That index includes antecedent year conditions and snowmelt, which do not materially affect Laguna Creek hydrology; therefore, we selected three representative wetness categories for the years investigated:

1. Wet – 2006 2. Average – 2003 3. Dry – 2002, 2004, 2005, 2007, 2008, 2009

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant 5 Hydrologic and Hydraulic Analysis

One mile downstream of WWTP discharge point

Figure 2. Example of Laguna Creek Cross-Section.

Half mile downstream of Laguna Creek and Cosumnes River confluence

Figure 3. Example of Lower Cosumnes River Cross-Section.

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant 6 Hydrologic and Hydraulic Analysis

3.2 EVAPOTRANSPIRATION

California Irrigation Management Information System (CIMIS) manages over 120 weather stations in California. RBI used the CIMIS Lodi Station evapotranspiration data for the last 10 years for this analysis. Evapotranspiration was applied to the top surface area in Laguna Creek and Lower Cosumnes River, which varied according to the flows. Table 2 below shows the monthly minimum, average, and maximum evapotranspiration at Lodi station from 2001 to 2010. For this analysis, the average monthly rate was used.

Table 2. Monthly Minimum, Average, and Maximum Evapotranspiration (in/day) at Lodi from 2001 to 2010. Min Average Max Month inches / day May 0.17 0.20 0.24 June 0.18 0.24 0.29 July 0.21 0.24 0.27 Aug 0.19 0.21 0.24 Sep 0.15 0.16 0.18 Oct 0.09 0.10 0.12

3.3 SEEPAGE

RBI used the Web Soil Survey (WSS) tool provided by U.S. Natural Resources Conservation Service (NRCS) to obtain soil data information for Laguna Creek. Approximately 80 percent of the area consists of Cosumnes Silt Loam, which has a moderately low to moderately high infiltration rate (Ksat = 0.06 to 0.20 in/hr). We expect that perched groundwater levels vary with wetness of the year and therefore affect seepage. Moreover, these top soils typically overlay less permeable layers, which can cause perched water levels.

Channel seepage rates for the Cosumnes River were evaluated in Mount et al. (2001) and estimated to be 1 to 2 cfs per river mile.

3.4 ADDITIONAL DOWNSTREAM DIVERSION

Anecdotal evidence suggests that Laguna Creek flow is diverted for irrigation downstream of Twin Cities Road. We estimated the diversion based on approximate irrigated land of 114 acres shown in Google Earth Images and City’s average field demand adjacent to Laguna Creek. Table 3 below shows the estimated monthly diversion from Laguna Creek below Twin Cities Road.

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant 7 Hydrologic and Hydraulic Analysis

Table 3. Estimated Monthly Diversion (cfs) from Laguna Creek below Twin Cities Road. Month Diversion (cfs) May 1.09 June 1.33 July 1.35 Aug 1.05 Sep 0.87 Oct 0.53

4 ANALYSIS

4.1 EXISTING CONDITIONS

We used the Excel-based model to estimate the flow and depth in Lower Cosumnes River at the tidal influence area by varying the Laguna Creek and Lower Cosumnes River seepage rates for the three wetness categories. The model showed that the Lower Cosumnes River has surface flow continuity from its confluence with Laguna Creek to the area of tidal influence during the months of September and October. Assessment of model output stream flow rates were cross- checked with representative aerial photos of seasonal Lower Cosumnes River flow conditions.

Table 4 below shows the flows in Laguna Creek upstream of the WWTP effluent discharge point (Inflow), flows in the Lower Cosumnes River just upstream of tidal influence (Outflow), and the corresponding water depth (Depth) under existing conditions. Changes in sections of the river that may already be deep enough for fish are not as relevant as minimum depth sections in the Lower Cosumnes River which dictate passage for migrating fish; hence, only flow in the Lower Cosumnes River just upstream of tidal influence area is shown in Table 4.

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant 8 Hydrologic and Hydraulic Analysis

Table 4. Flows (cfs) in Laguna Creek Upstream of the Discharge Point (Inflow), Lower Cosumnes River just Upstream of the Tidal Influence Area (Outflow), and the Corresponding Depth (ft) under Existing Conditions for Wetness Categories. Wet Average Dry Month Inflow Outflow Depth Inflow Outflow Depth Inflow Outflow Depth cfs ft cfs ft cfs ft May 14.07 10.70 1.26 9.06 5.78 0.92 6.77 2.60 0.62 June 7.30 3.85 0.76 3.74 0.00 0.00 4.63 0.34 0.20 July 2.23 0.00 0.00 2.60 0.00 0.00 1.05 0.00 0.00 Aug 8.73 3.92 0.77 5.26 0.00 0.00 3.57 0.00 0.00 Sep 9.82 5.18 0.88 7.01 1.32 0.45 6.08 0.53 0.27 Oct 13.51 7.46 1.07 12.98 6.95 1.04 13.37 7.32 1.06

4.2 PROJECT CONDITIONS

The City proposes to discharge the effluent from the Wastewater Treatment Plant (WWTP) after meeting irrigation demand. RBI estimated the City’s irrigation demand using the average of City’s field demands in 2003, 2006, 2007, 2008 and 2009. 2010 field demand data was provided by the City after the modeling was completed and was not used in this analysis as the change in the estimated monthly discharge from the WWTP with the inclusion of 2010 was very minimal. Table 5 shows the estimated resultant discharge from WWTP, based on design production rate of 4.65 cfs (3 MGD) and after meeting the irrigation demand.

Table 5. Estimated Monthly Discharge from the WWTP. Month Discharge (cfs) May 3.01 June 2.52 July 2.49 Aug 2.79 Sep 3.17 Oct 3.86

Table 6 below shows the flows in Laguna Creek at the discharge point, including WWTP discharge (Inflow), flows in Lower Cosumnes River just upstream of the tidal influence area (Outflow), the corresponding depth (Depth), and the change in depths (Diff) near the tidal influence area under Project conditions, which includes the additional estimated monthly effluent discharge from the WWTP.

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant 9 Hydrologic and Hydraulic Analysis

Table 6. Project Flows (cfs) in Laguna Creek at the Discharge Point Including WWTP discharge (Inflow), Flows in the Lower Cosumnes River just Upstream of the Tidal Influence Area (Outflow), the Corresponding Depth (ft) and the Change in Depths (Diff) at the Tidal Influence Area under the Project Conditions for Wetness Categories. Wet Average Dry Month Inflow Outflow Depth Diff Inflow Outflow Depth Diff Inflow Outflow Depth Diff cfs ft cfs ft cfs ft May 17.08 13.65 1.38 0.12 12.07 8.73 1.14 0.22 9.78 5.33 0.89 0.27 June 9.82 6.26 0.96 0.20 6.26 1.87 0.53 0.53 7.15 2.55 0.60 0.40 July 4.72 0.65 0.29 0.29 5.09 0.68 0.29 0.29 3.53 0.00 0.00 0.00 Aug 11.52 6.58 1.01 0.24 8.06 1.86 0.53 0.53 6.37 0.55 0.27 0.27 Sep 12.99 8.23 1.11 0.23 10.18 3.93 0.77 0.32 9.25 3.07 0.68 0.41 Oct 17.37 11.06 1.27 0.20 16.84 10.55 1.25 0.21 17.23 10.93 1.26 0.20

4.3 MODEL SENSITIVITY

The strength of the model is in the ability to assess the change in water surface elevation under variable flows. Because the range of flows seems reasonable, and at the estimated depths the side walls are roughly straight, changes in existing condition should not materially affect the influence of the effluent discharge (i.e., the change should remain in the order of 0.2 to 0.3 feet).

As no stream gauges are currently available on Laguna Creek, flows were estimated using the total monthly discharge from Rancho Seco and the total monthly GID usage. Hence, the estimated average daily flows represent the flows over the course of the month.

5 CONCLUSION

The model shows the Lower Cosumnes River has continuous surface flow from its confluence with Laguna Creek to the area of tidal influence in September and October under existing conditions. Historical Google Earth aerial photographs also show surface flow continuity during these months. The addition of City’s proposed effluent discharge would increase the water depths in the Lower Cosumnes River just upstream of the area of tidal influence by an average of 0.32 feet during September and 0.20 feet during October.

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant 10 Hydrologic and Hydraulic Analysis

6 REFERENCES

Mount, J., G.E. Fogg, L. Kavaas, J. Fleckenstein, M. Anderson, Z.Q. Chen, and E. Suzuki. 2001. Linked Surface Water-Groundwater Model for the Cosumnes River Watershed: Hydrologic Evaluation of Management Options to Restore Fall Flows. Sponsor: U.S. Fish and Wildlife Service Anadromous Fish Restoration Program Cooperative Agreement No. 11332-8-J264. (September). Available at: <>.

City of Galt Summer Surface Discharge Project Robertson-Bryan, Inc. City of Galt Wastewater Treatment Plant 11 Hydrologic and Hydraulic Analysis