EXHIBIT 1-D
WATER RECLAMATION AND RECHARGE
PROJECT DESCRIPTIONS
FOR
THE IRWMP PLANNING GRANT APPLICATION
3.3.2 Expand Water Reclamation Efforts
The Monterey
Regional Water Pollution Control Agency (MRWPCA) has been pursuing several
recycled water projects, which are briefly described below. The largest of these, the Monterey County
Water Recycling Projects, was completed and put into service in 1998. The other projects are in various stages of
planning, and should be ready to move forward into design and construction in
the near future. These projects will be
included as part of the IRWMP to be developed under this application, thereby
helping to expand the amount of reclamation throughout the planning area. The use of recycled water will reduce the
demand on potable water supplies, and will be an integral part of the overall
water management planning effort.
The Monterey County Water Recycling Projects (MCWRP) is comprised of
two components – the treatment component and the distribution component. The treatment component is the Salinas Valley
Reclamation Project (SVRP), and the distribution component is the Castroville
Seawater Intrusion Project (CSIP). The
MCWRP was completed and placed into service in 1997. The MCWRP is designed to recycle over 32,000
acre-feet-per-year, when influent flows to the SVRP reach that level. At current flows and demands the MCWRP is
supplying over 13,000 AFY to irrigate 12,000 acres of food crops being grown in
the Castroville region of the lower
The SVRP provides the
following treatment processes:
· Pumping of effluent from the existing
secondary level treatment plant to the new reclamation plant
· Rapid mixing of coagulant and flocculent chemicals
· Flocculation
· Dual media gravity filtration
· Disinfection using gaseous chlorine
· Diurnal flow equalization storage
The CSIP is comprised
of:
· 46 miles of reclaimed water
transmission and distribution pipeline ranging in diameter from 8 inches to 51 inches
· 22 supplemental groundwater wells (to
augment reclaimed water flows at times of peak demand)
· 111 flow-metered turnouts for connection of irrigation
piping by growers
· Pressure, conductivity, and flow monitoring stations
· A centralized control system
· 3 booster pumping stations
· Cathodic protection for ferrous metal piping
Regional Urban Recycled Water
Project
The Regional Urban Recycled Water
Project (RURWP) will provide irrigation water to numerous golf courses, parks,
and landscaped areas in the
This project is in the late planning stage. A project report (“Regional Urban Recycled Water Distribution Project”, dated July 2003 prepared by RBF Consulting for MRWPCA and the Marina Coast Water District) has been completed. It analyzed various alternative project sizes and configurations and identified the recommended project. A program level EIR that covers this project has been completed (“Final Environmental Impact Report for the Marina Coast Water District Regional Urban Water Augmentation Project”, dated September 2004 prepared by Denise Duffy and Associates in association with RBF Consulting), and this has been certified by the Marina Coast Water District Board of Directors. Thus, following completion of institutional and financing arrangements, the project will be ready to move forward into the design stage.
Seaside Basin Groundwater
Replenishment Project
The proposed Seaside Basin Groundwater
Replenishment Project (GRP) involves the purification and conveyance of
recycled water from MRWPCA’s Salinas Valley Reclamation Plant (SVRP) for
recharge of the
The product water would meet all
drinking water standards prior to groundwater recharge. State guidelines for groundwater recharge of
purified recycled water require that the water be blended with water from
non-wastewater sources. The blend water
could come from the
The Seaside Basin Groundwater Replenishment Project would work in
parallel with the ASR project being pursued by the MPWMD on this same
basin. The
This project is in the early planning stage. An initial feasibility study has been completed (“Feasibility of Using Recycled Water to Recharge the Seaside Groundwater Basin in Monterey County”, dated September, 2004 prepared by William R. Mills, PE, RG, DDE). Follow-on work is in progress involving coordination with other agencies, analyzing available hydrogeologic data for the proposed recharge sites, identification of environmental, permitting, and approval issues, development of criteria and parameters for a pilot-scale recharge facility, and preparation of a design report.
New Section 5.2.X
5.2.X Regional
Urban Recycled Water Project
The Regional Urban Recycled Water Project (RURWP) will provide
irrigation water to numerous golf courses, parks, and landscaped areas in the
The RURWP facilities will include a pipeline distribution system, pump stations, and storage tanks and reservoirs.
The distribution system will deliver recycled water though a trunk line and a series of laterals to each of the reuse sites. These facilities were sized based on a conservation irrigation demand scenario. This was developed by taking into account adjustments to existing application and water management efficiencies that could reasonably be achieved by using improved management and water conservation practices. Pipeline alignments were selected to maximize the use of existing public rights-of-way for pipeline construction and maintenance activities, minimize the need to acquire new rights-of-way in order to cross private and CSUMB lands, comply with State requirements for separation between potable water pipelines and recycled water pipelines, and to be consistent with roadway and utility system development plans throughout the former Fort Ord.
There will be two pump stations to provide adequate operating pressure throughout the distribution system. One will be located at the SVRP and one at an appropriate location within the distribution system.
Operational storage will be provided by an earthen reservoir
at the Salinas Valley Reclamation Plant (SVRP) and a conventional above-ground
storage tank located within the service area. These will enable peak irrigation
demands to be met with less peak pumping capacity than would be the case without
such storage. Seasonal storage refers to the storage of recycled water produced
during the low-demand winter months, so additional water can be made available
during the high-demand summer months. No seasonal storage will be needed to
serve the Phase I demands. However,
seasonal storage will be a necessary component of the Phase II project. Options available for seasonal storage were
identified as Aquifer Storage and Recovery and a surface storage reservoir at
Armstrong Ranch.
The recycled water project will be constructed in at least two phases, so that water demands will match the available supply, and also to keep the costs of recycled water in a competitive range compared with other water supplies. Phase I is projected to be complete in 2008, and would provide service to the largest existing customers, as well as other developments that are expected to be complete by 2007. Phase II could be complete by 2010. However, the Phase II construction schedule would be tied to the readiness of the Phase II users
It is estimated that the unit cost of recycled water can be
reduced by approximately $30/AF for every million dollars of capital cost
reduction achieved from capital cost contributions. Therefore, funding
assistance from grants or other sources will greatly enhance the viability of
this project by helping to keep recycled water costs competitive with potable
water costs. Other sources of capital contributions could include developer
contributions, connection fees, and development fees collected on the former
New Section 5.2.Y
5.2.Y
The proposed Groundwater Replenishment Project (GRP) for the
During the summertime, the SVRP produces tertiary treated
water from the effluent of the Regional Wastewater Treatment Plant. This recycled water meets all State and
Federal standards for irrigating golf courses, parks, schools, and agricultural
crops, including non-processed food crops which may be eaten raw. Currently, only agricultural applications are
made, as a conveyance and distribution system for urban uses does not
exist. However, construction of an urban
water supply system, the Regional Urban Recycled Water Project, to provide irrigation
water for the southern
Recycled water from the SVRP would be purified by an advanced wastewater treatment plant (AWT). The AWT would most likely be constructed adjacent to the SVRP, although alternate locations will be considered during preliminary design. The AWT would process water to meet all State and Federal drinking water standards and the California Department of Health Services (DHS) requirements for groundwater recharge. The treatment processes would most likely include reverse osmosis (RO) for the removal of dissolved salts, microorganisms, and other constituents. An ultraviolet disinfection system would be provided to meet bacterial requirements and for destruction of organic compounds. The ultraviolet system might be coupled with the addition of hydrogen peroxide, if necessary to improve its effectiveness.
The SVRP should provide adequate pretreatment for the RO process. However, it may be desirable to include pretreatment with microfiltration to reduce biofouling of the RO membranes.
The purified water would be recharged either through surface
recharge basins or by injection wells. In either case, the recharge facilities would
be constructed on the former
Direct Injection into the
Aquifers: MPWMD’s pilot demonstration project has shown
that direct injection of potable water into the Santa Margarita aquifer is
feasible. This aquifer is the primary groundwater supply in the
Surface Recharge using Recharge
Basins: The U.S. Geological Survey has previously
investigated the feasibility of surface recharge in the
The former
Recharge water would travel downward through the Aromas Sand into the Paso Robles Formation and then probably into the Santa Margarita. (The percolation pathways into this confined Santa Margarita aquifer are not currently well defined.) The percolation of the AWT water through the Aromas Sands would further purify the percolating waters.
While the upper layers of soil are conducive to surface recharge, subsurface clay lenses within the underlying aquifers could serve to possibly inhibit or retard the downward percolation of water. Therefore, if this recharge method is selected for further consideration it would be necessary to perform a pilot recharge test to determine the degree of retardation provided by these restricting layers.
The purified water would be transported to the groundwater recharge or injection site via a pipeline during the winter period when agricultural and urban irrigation demands are minimal. The RO process usually rejects about 10% of the influent as a brine stream. The brine stream would most likely be discharged into the brine disposal facility at MRWPCA’s Regional Wastewater Treatment Plant, although alternate disposal methods will be considered during preliminary design.
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