PROGRESS REPORT ON PRELIMINARY BRINE DISPOSAL SCREENING ANALYSIS

Transcription

1 PROGRESS REPORT ON PRELIMINARY BRINE DISPOSAL SCREENING ANALYSIS MAY 2015 SUMMARY In 2002, the California Regional Water Quality Control Board-Los Angeles Region ( Regional Board ), a state agency, adopted a regulatory order called the Upper Santa Clara River Chloride Total Maximum Daily Load ( Chloride TMDL ). This order imposes a strict limit on the level of chloride (salt) in the treated wastewater discharged to the Santa Clara River from the Valencia and Saugus Water Reclamation Plants ( WRPs ). The Regional Board later extended the compliance deadline from May 2015 to July 2019; however, the Santa Clarita Valley Sanitation District ( District ) faces significant fines if it does not meet this final deadline. The Santa Clarita Valley Sanitation District Facilities Plan and Environmental Impact Report ( Facilities Plan and EIR ) contain a detailed analysis of potential projects to achieve compliance with the State-mandated Chloride TMDL. On October 28, 2013, the District Board of Directors ( District Board ) approved a project alternative from the Facilities Plan and EIR (approved compliance project) and certified that the EIR was completed in accordance with the California Environmental Quality Act ( CEQA ). Under the approved compliance project, ultraviolet light ( UV ) disinfection would replace the existing chlorine-based system at both the Saugus and Valencia WRPs, and a portion of the Valencia WRP effluent would receive advanced treatment using microfiltration and reverse osmosis ( MF/RO ) to remove chloride. The advanced treatment facility would produce a brine waste (salty water) that would, under that option, be disposed of by deep well injection. At its March 11, 2015 meeting, the District Board directed staff to investigate locations for deep well injection not near homes. The District Board also directed that the staff investigate additional brine management alternatives, including newer technologies. Based upon the staff s preliminary evaluation of feasibility to complete the project by the required compliance deadline, neither deep well injection nor pipeline alternatives could be implemented by the regulatory deadline. Brine minimization with disposal by trucking is the only alternative identified that could be implemented within the timeline mandated by the Regional Board. An environmental analysis of brine minimization at the Valencia WRP with disposal of brine by trucking at an appropriate existing disposal location should be included in future environmental documents along with any other alternatives that may merit further investigation. The brine would not be trucked to East Los Angeles as previously proposed. More information on the assessment of alternatives as currently ongoing is presented below. Santa Clarita Valley Sanitation District 1 May 2015

2 BACKGROUND Under the Federal Clean Water Act and the state s Porter Cologne Act, the Regional Board regulates discharges to the Santa Clara River to protect beneficial uses of the river s water. As part of this regulatory power, the Regional Board adopted the Chloride TMDL in The Chloride TMDL imposes a strict limit on the level of chloride that may be contained in the treated wastewater discharged by the Valencia and Saugus WRPs. The Regional Board later extended the compliance deadline from May 2015 to July The District faces significant fines if it does not meet this final deadline. After the Chloride TMDL was first issued, the District spent more than ten years attempting to achieve the most reasonable chloride limit possible and seeking the least costly solution for meeting the State-mandated chloride limit. The District s two wastewater treatment plants are not designed to remove chloride. To meet the Chloride TMDL and to avoid the regulatory penalties, including fines, for noncompliance, the District must design and construct new wastewater treatment facilities for chloride reduction. The Facilities Plan and EIR include and describe the technical studies completed to identify cost-effective and environmentally sound methods of meeting the State mandated chloride limit. On October 28, 2013, the District Board approved the alternative from the Facilities Plan that appeared to best meet these criteria and certified the associated EIR. Under the approved compliance project, a portion of the Valencia WRP s effluent would receive advanced treatment using MF/RO. The ultra-clean water from the MF/RO would be blended with the Valencia WRP effluent and discharged to the river to achieve compliance with the chloride limit. The existing chlorine-based disinfection systems at the Valencia and Saugus WRPs would be replaced with UV disinfection facilities. The advanced treatment facility would produce a brine waste that was in the approved project to be disposed by deep well injection. A new pump station and pipeline was proposed to convey brine from the Valencia WRP to a deep well injection site located approximately two miles south of the plant. The District learned after the certification of the EIR that the specific parcel of land that was the preferred site for the deep well injection was no longer available for development because of a conservation easement. The District proposed deep well injection on an alternate site at the south end of the Tournament Players Club golf course ( TPC site ), which is approximately 800 feet north of the location previously analyzed. A Draft Supplemental EIR was prepared that evaluated the potential environmental impacts associated with the alternate deep well injection site. RECENT DISTRICT BOARD DIRECTION During the public review period for the Draft Supplemental EIR, community representatives expressed significant concern about the proposed TPC site. At its March 11, 2015 meeting, the District Board rejected the use of the TPC site and any other injection locations near the Stevenson Ranch and Westridge communities. The District Board withdrew the Draft Supplemental EIR from further consideration, and directed staff to investigate and evaluate other locations for deep well injection not near homes, allowing appropriate time for input and Santa Clarita Valley Sanitation District 2 May 2015

3 environmental review under CEQA for another site. Also, the District Board directed staff to investigate other alternatives, including newer technologies such as those that reduce the volume of brine requiring disposal. ALTERNATIVES FOR BRINE DISPOSAL Below are brief descriptions of the brine disposal alternatives and a preliminary screening analysis of these alternatives. Deep Well Injection Deep well injection involves the discharge of brine through wells constructed deep in the ground below the water supply. Although this is a proven method of brine disposal used throughout the state, there is significant doubt whether this alternative can be implemented by the compliance deadline. After conducting a siting study of potential sites away from homes, the District would need to complete technical studies, negotiate property rights with land owners, obtain a permit from the U.S. Environmental Protection Agency, and, likely, a Conditional Use Permit from Los Angeles County to build a test well to verify that a new site that may be identified is viable. Then, subsequent design and construction of operating wells and a pipeline to carry brine from Valencia WRP would be needed. The brine pipeline would also require property negotiations and permits from local jurisdictions. Each of these steps requires cooperation by an outside party to complete in a timely fashion and there is high potential for delay. Given the amount of time left to complete a project by the July 2019 deadline, it is unlikely that such a project could be completed by this deadline. Brine Pipeline A pipeline and pump stations could be used to convey brine to a suitable discharge location outside the Santa Clarita Valley. The two best route options identified in the Facilities Plan were pipelines to the Los Angeles Basin and to the Calleguas Salinity Management Pipeline in Ventura County. The Los Angeles Basin pipeline was rated superior in part because it had the greatest likelihood of completion before the compliance deadline relative to other pipeline routes. At this point, no pipeline to the Los Angeles Basin appears likely to be completed by the compliance deadline. Designing and constructing a 37-mile pipeline through older communities that already contain many subsurface utilities would be a time-consuming undertaking. Even if the pipeline were divided into multiple segments for concurrent construction, there is a low probability of completing the pipeline within the compliance deadline. Also, pipeline construction would require the issuance of construction permits by several jurisdictions including unincorporated Los Angeles County, and the cities of San Fernando, Los Angeles, Burbank and Glendale. Obtaining these permits would be a lengthy process that could impact the project schedule and could result in onerous permit requirements that add to project costs. In March 2015, the City of Ventura expressed interest to the District and other potential stakeholders about a shared regional brine pipeline. The City of Ventura is subject to Regional Board requirements that are likely to require advanced treatment and disposal of the resulting brine. The City of Ventura has until 2020 to propose a compliance option to the RWQCB and Santa Clarita Valley Sanitation District 3 May 2015

4 until 2025 to implement whatever compliance option is selected. Given this time frame, a partnership with the City of Ventura is not an option. In addition, estimated costs for a pipeline have also increased since the Facilities Plan was completed. Technical information recently obtained as well as information from the operator of a brine line in the Inland Empire indicates that brine may need to be softened to avoid extensive scaling of the pipeline. The final pipeline design would need to include a detailed analysis to determine the level of control needed to manage scaling. Brine Minimization with Disposal by Trucking Section of the Facilities Plan and EIR evaluated different levels of brine minimization with disposal by trucking. Brine minimization would involve the use of mechanical equipment located at the Valencia WRP to concentrate the brine and reduce the number of truck loads per day needed for disposal. In a typical RO system without brine minimization, 85 percent of the water treated becomes product water (ultra-clean water) leaving 15 percent brine. A number of different processes could minimize the quantity of brine for disposal, including some that would result in over 99 percent product water and less than one percent brine. Some processes like secondary RO (also sometimes referred to as second-pass RO), are emerging technologies. Others, like softening followed by secondary RO, have been successfully used for treatment of drinking water and industrial waste but have not been used extensively with municipal wastewater. Several brine minimization processes could be used in combination to achieve various levels of brine reduction. Most of these processes are sensitive to the chemistry of the water being treated, which means that the water composition being fed to the process can impact the chemicals and energy required to operate the process, and thereby, impact costs. In the Facilities Plan, the three brine minimization options considered were: secondary RO, softening plus secondary RO, and softening plus secondary RO plus partial evaporation. These options would result in a maximum of 90, 45 and 5 truck trips per day for brine disposal, respectively. The first option was selected as the brine minimization process for that alternative because it had the lowest cost, minimized chemical use and space requirements, and avoided potential operational complications that could result from the use of the other two options. Due to the large number of daily truck trips, the haul distance, with its associated costs and environmental impacts, needed to be minimized. In view of concerns raised in comments on the Facilities Plan and EIR, the District is now considering reduced trucking options where brine minimization equipment would be used to reduce the number of trucks to a relatively small number per day. This analysis is at a preliminary phase, but it is possible that the resulting number of truck trips for disposal could be reduced to as few as 5-10 round trips per day. One brine minimization approach discussed in the Facilities Plan and EIR was enhanced membrane systems. These processes require softening and ph adjustment (to control scaling and organic fouling), and additional stages of RO membranes. In the Facilities Plan, the District stated that these technologies were not fully proven or were prohibitively expensive and that staff would monitor the development of these technologies and may recommend future implementation. The technologies have been installed in more applicable installations in the interim and appear to be operating successfully. Other technologies such as evaporators and Santa Clarita Valley Sanitation District 4 May 2015

5 crystallizers are under consideration to further minimize brine, but these technologies may require higher capital investment, more energy, and thus, higher operating costs. District s staff and expert consultants are still evaluating a number of relatively new brine reduction technologies and combinations of these technologies for brine minimization. This alternative has several important benefits that have been identified to date. First, the environmental impacts during construction and operation of the brine minimization equipment would be constrained to the Valencia WRP, an existing industrial facility. Second, this alternative has the highest ability to meet the regulatory deadline because there are limited external approvals required. Third, this alternative appears to have a similar range of capital but potentially higher O&M cost than the approved compliance project. Depending on the cost, it is likely that the project can be implemented within the rate structure approved in Based upon this preliminary analysis above, brine minimization with disposal by trucking appears to be the most promising alternative of those identified to date. However, once full scale operation begins, the need for more chemical use or higher maintenance requirements than anticipated could result in higher operating costs. Other aspects of brine minimization that need to be further evaluated include equipment manufacturing lead times and space requirements for constructability within the limited footprint remaining at the Valencia WRP. NEXT STEPS Brine minimization at the Valencia WRP with disposal of brine waste by trucking at an appropriate existing disposal location is the only alternative identified to date that could be implemented by the regulatory deadline. District staff and expert consultants will continue to evaluate these technologies. As next steps, pending direction from the District Board, District s staff would complete an environmental evaluation of project alternatives. The CEQA process would commence in summer 2015 with public scoping meetings in late summer. There would be information meetings this fall to provide an update on the overall project and a draft environmental document would be targeted for public review in early The goal of this process would be consideration by the District Board of a final environmental document in summer Santa Clarita Valley Sanitation District 5 May 2015