Response to Comment 401-001

Robin Cort

Informations

• Publié par: Udwe
• Nombre de lectures: 13
• Langue: English

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INDSOR

Response to Comment 401-1

Comment Summary: The comment expresses concern about the Town of Windsor’s potable

water supply, which comes from the Russian River and a Russian River well field along

Eastside Road as well as from the Sonoma County Water Agency.

Appendix I.1 of the Draft EIR contains a human health risk assessment which evaluates

impacts of exposure to recycled water. As noted on page I.1-9 of Appendix I.1, “The IRWP

is evaluating an additional direct discharge component that would release recycled water

from a new outfall on the Russian River between Healdsburg and Mirabel.

A possible

exposure pathway from direct discharge into the Russian River includes movement of surface

water to groundwater where it could theoretically reach a water supply well or other intake

(private or municipal).

The IRWP is also evaluating three indirect discharge options.

Possible exposure pathways that could result from indirect discharge include movement of

recycled water via groundwater to a domestic well where it may be used as a domestic water

supply and movement of recycled water via groundwater to a nearby waterway (e.g., Russian

River).” Page I.1-12 states that “potential exposure pathways include domestic water supply,

fish consumption, recreational use and irrigation. The domestic water supply, recreational

use and fish consumption pathways would include dilution of recycled water with surface

water or groundwater between the release point (e.g., Russian River discharge, reservoir

leakage) and the exposure point (e.g., domestic water use, recreational water use).

For

purposes of screening, however, no dilution or other mitigating factors were considered in

the risk assessment.” The Risk Assessment found that the exposure to recycled water would

not present a significant human health hazard.

Response to Comment 401-2

Comment Summary:

This comment suggests that the Supporting Program Objective to

provide flexibility to accommodate recycled water from neighboring agencies as deemed

appropriate by the City of Santa Rosa should be made primary rather than secondary

because of the common interests shared by several communities in the Russian River basin.

The IRWP EIR responds to the Program Objectives adopted by the City of Santa Rosa, as

managing partner of the Subregional Water Reclamation System, on September 4, 2001. It is

not within the scope of this EIR to change the Program Objectives, but this request will be

passed on to the Board of Public Utilities and City Council for their consideration.

Response to Comment 401-3

Comment Summary:

The comment asks how proposed project sites for water storage

facilities would be screened and chosen if an alternative requiring storage is chosen.

Please refer to Response to Comment 202-36.

OCTOBER 20, 2003

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PAGE 401-1

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PAGE 401-2

Response to Comment 401-4

Comment Summary. The comment states that for Alternative 6B, a discharge site between

north Healdsburg and Mirabel was identified and asks how the final location for the site

would be screened and chosen. Are there other downstream locations that would be as

attractive or more attractive, considering all factors? The potential for surface water quality

and human health impacts should be carefully considered. A discharge location downstream

of Mirabel would be downstream of the Russian River wells for the Town of Windsor and the

water supply intakes of the SCWA.

Detailed technical studies are necessary to determine the most appropriate discharge location,

and a selection will be made in a public process. As indicated in Figure 1 of Technical

Memorandum 8 (Santa Rosa Incremental Recycled Water Program – Discharge) the general

study area for direct discharge extends slightly downstream of Mirabel, so a new discharge

location could potentially be located downstream of both SCWA and Windsor water intakes.

The location of the SCWA and Windsor intakes would be one factor considered in selecting

an appropriate discharge site. If Alternative 6B were selected, project-specific environmental

review would be required, which could include analysis of impacts associated with the

proposed location of the discharge.

Response to Comment 401-5

Comment Summary. The comment states that the Direct and Indirect Discharge Alternatives

have significant impacts to surface water quality before and after mitigation which could

adversely impact the potable water supply for the Town of Windsor and the SCWA if the

discharge locations are upstream of these water supply intake locations.

The only significant impact after mitigation identified for direct and indirect discharge is for

cyanide. As discussed in Chapter 4.6 page 4.6-62, the concentrations of cyanide in recycled

water may be an artifact of analytical methodology. In addition, the maximum recorded

concentration of cyanide in Santa Rosa’s effluent during the period covered by the Draft EIR

is 16 μg/L (Table 4.6-2) which exceeds the criterion for aquatic life (thus the determination

of a significant impact), but is far below human health standards. For example, the CTR

criterion for cyanide for the protection of human health is 700 μg/L for the consumption of

water and organisms. Thus, the concentrations of cyanide in recycled water are unlikely to

have an adverse impact on the potable water supply for the Town of Windsor and the SCWA.

Response to Comment 401-6

Comment Summary: The comment references statements in the Draft EIR concerning the

reduction in agricultural irrigation in the Laguna, and states that not including continued

full irrigation of lands in the Laguna under Alternative 4 of the IRWP could be a substantial

omission in the Draft EIR.

The City of Santa Rosa agrees that existing agricultural irrigation of City-owned farms in the

Santa Rosa plain should be included under Alternative 4 of the IRWP.

Alternative 4C

Agricultural Reuse on City-owned Farms in the Santa Rosa Plain has been added to the

analysis in Chapter 3, Lead Agency Revisions.

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PAGE 401-3

Response to Comment 401-7

Comment Summary: The comment suggests that Alternative 4 should consider the expansion

of agricultural irrigation in the Laguna.

The existing program of agricultural reuse in the Santa Rosa plain irrigates approximately

6,700 acres with recycled water. Although slight expansions of this existing program might

be possible, most of the cultivated and irrigable land in the Santa Rosa plain is already

included in the program. A potential expansion of the existing system would not dispose of

enough recycled water to be worth considering in the IRWP.

Response to Comment 401-8

Comment Summary. The comment asks what periods of time are proposed for direct and

indirect discharges and what are the proposed volumes of the discharges.

Both direct and indirect discharge would be limited to October through May. Table 4 (page

11) of the Draft Feasibility Report presents total projected discharge volumes. Technical

Memorandum 16 (Water Balance Summary) presents more detailed information on projected

discharge volumes under a number of scenarios and environmental conditions.

These

discharge volumes were not pegged to a certain percentage of river flow.

The dilution

calculations in Technical Memorandum 16 account for SCWA future diversions and releases.

Response to Comment 401-9

Comment Summary. The comment asks what regulatory permits would be required for direct

and indirect discharge and if a new or modified NPDES permit would be obtained. The

comment also asks if the discharges would be consistent with the existing Basin Plan or

would significant exceptions be required.

The regulatory permits required are summarized in Chapter 2 page 83. They are described in

detail in Technical Memorandum 9 (Santa Rosa Incremental Recycled Water Program –

Regulations and Approvals for IRWP Alternatives).

A new NPDES permit would be

obtained.

Two exceptions to the Basin Plan may be required for IRWP discharge:

an

exception to discharge over the 1% of the Russian River flow limitation; and an exception to

the requirement for advanced wastewater treatment if the secondary flow option during storm

events is selected. Please refer to Response to Comment 202-16 regarding the Basin Plan

Amendment for discharges of secondary effluent.

Response to Comment 401-10

Comment Summary: The comment asks how sites for indirect discharge would be screened if

this option were selected, and suggests that facilities should be sited to provide flexibility for

accommodating recycled water from neighboring agencies.

Appendix N.2 of the Draft EIR, Technical Memorandum 10, Indirect Discharge, develops

evaluation criteria for site suitability for indirect discharge. Criteria consider surface soil

conditions, geology, hydraulic conditions, location of historical river channels, topography,

floodplain areas, land use, and proximity to existing wells. If individual projects including

indirect discharge are selected for implementation, the siting of the facilities would be subject

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PAGE 401-4

to supplemental CEQA review, including evaluation of alternative discharge sites. Also refer

to Response to Comment 401-3 regarding Mitigation Measures that establish some of the

requirements for siting of facilities. The City of Santa Rosa could consult with neighboring

agencies regarding siting of facilities.

Response to Comment 401-11

Comment Summary: Are the “existing facilities” described as being used as infiltration

basins active or retired quarry pits and where are they located?

For the purposes of the EIR it was assumed that there was a possibility of using existing

active or retired quarry pits as infiltration basins to accomplish indirect discharge to the river.

Figure 2-3 in the Draft EIR identifies the areas along Dry Creek and the Russian River where

facilities could be located.

Specific facilities have not been identified at this time.

Supplemental CEQA review, including an evaluation of specific alternative sites, would be

required before implementing this component. Also refer to Master Response G – Program

versus Project EIR Studies for additional information regarding program EIRs.

Response to Comment 401-12

Comment Summary. The 6° F temperature rise in the Russian River for the 95

th

percentile

case appears to be substantial and exceeds the Basin Plan Criterion.

The City of Santa Rosa agrees. In the Draft EIR the impact of discharge on temperature in

the Russian River was determined to be significant before mitigation, but less than significant

after mitigation.

Response to Comment 401-13

Comment Summary: The comment suggests that the City place emphasis on providing

agricultural irrigation to the Laguna and to South and West County users (as proposed in the

Long-Term EIR) so that the Town of Windsor can provide recycled water to users in the

Windsor and Russian River areas.

Please refer to Master Response A – Statements of Opinion for or against a Program

Alternative or Component. The City of Santa Rosa could cooperate with other jurisdictions

adjacent to potential irrigation areas in the development of any future irrigation projects.

The City of Santa Rosa can implement projects in areas evaluated in the Long-Term EIR.

The IRWP EIR is not intended to rule out the use of lands already analyzed in the Long-

Term EIR. The City could proceed with irrigation on such other lands at its discretion,

subject to the requirement to perform supplemental environmental review if required.