Regional H2O Quality Control Board and Stakeholders Respond to City Sewer Report
• Number of Unknowns Increases as Additional Factors that May Impact Project Results Are Identified
The Regional Water Quality Control Board indicated last week its review and public comments from environmental groups, homeowners and the public about the City of Malibu’s reports on recycled water use and storage, the results of phase one work on the disposal of wastewater by injection well and the conceptual groundwater injection plan are available for review.
“The Regional Board staff has performed a detailed review on all three reports. The recycled water study has identified the existing and potential wastewater reuses and possible storage alternatives,” a RWQCB letter to the city states.
“The well test report has provided additional hydrogeological information in the Malibu Civic Center area. And the conceptual plan has modeled the hydrogeological responses to estimate the possible groundwater storage capacity by using the well test results,” the letter goes on to state.
“The information contained in the conceptual reports is sufficient for initial evaluation. The city also demonstrated its intent in continuing to achieve toward the goal of constructing a centralized wastewater treatment plant,” the RWQCB letter continued.
Those RWQCB comments are accompanied by pages of requests for clarifications that should be addressed by Malibu officials in the final reports.
However, Heal the Bay and The Waterkeeper and several Malibu residents recommended the water board reject the conceptual plans until much further study has been done.
Groundwater injection for wastewater disposal has become the preferred method, encouraged by the water boards, when the city began its feasibility tests to confirm the viability of groundwater injection of the treated effluent in the Civic Center area and the estimated groundwater injection capacity in that area.
The tests were to determine if up to 500,000 gallons of effluent can be injected on a daily basis. The current number used today is 347,000 gallons per day.
Heal the Bay has urged the water board to reject the city’s injection plan technical memo. They assert that groundwater injection is not a viable option until the unknown impacts to Malibu Lagoon are known.
“The plan lacks the necessary details to support [the city’s] conclusion. We are concerned that the injection plan as written does not adequately address potential impacts the project may have on the soon-to-be restored Malibu Lagoon,” the Heal the Bay letter states.
Three exploratory test wells were installed to bedrock. Pumping tests were conducted to each of the wells to measure local aquifer hydraulic properties. If the tests show that the Civic Center gravels are reasonably transmissive, more in-depth investigative work may be conducted.
Heal the Bay’s comments note that the injection plan memo states that about 20 percent of the injected water is predicted to travel through the groundwater flow system and ultimately discharge to Malibu Lagoon if all three phases of the septic prohibition are implemented.
“This is of particular concern because the anticipated quality of the effluent to be injected will be high in nutrients.”
Another concern of the enviro groups is the lack of information about seismic impacts to existing groundwater aquifers and beneficial uses within these aquifers.
Water sampling tests will be taken along with other water testing and analysis will be done including an assessment for the potential for adverse geochemical reactions that could occur with groundwater injection of treated wastewater. Aquifer properties will be measured and other related water sample tests undertaken.
“One important consideration in assessing the feasibility of groundwater injection into an area is the seismic and potential geohazards in the vicinity of the injection project. The injection plan technical memo should therefore analyze the impact of a potential seismic event on the city’s plans to inject groundwater near the Civic Center. The plan should evaluate the possibility of the injection of water to aggravate the earthquake fault. The plan should include a desktop analysis to identify and assess potential significant earthquake-induced ground shaking or fault rupture risks and the associated consequences to other Civic Center areas that could either impact or result from the wastewater injection into the geologic formations underlying Malibu. Could [it[ lead to increased potential for soil liquefaction, which could impact structures in the Civic Center area?” wrote Heal the Bay’s environmental engineer W. Susie Santilena.
It is the same theme hammered on by Malibu activist Hans Laetz, who said there was too scant information in the city’s report to inform the city or the water board.
Malibu Road attorney Joan Lavine, who is doing battle in the courtroom with the water board over the legality of the septic ban. notes that she and other homeowners have the deeded rights to the underground water, mineral, oil and gas rights.
“Interference with those rights is subject to ‘takings’ and compensation by the governmental entities engaged in the interference under [state] law,” she wrote.
The reports by the city are in response to the Memo of Understanding entered into by Malibu and the water boards regarding phased implementation in the Malibu Civic Center.
In the MOU, the city agreed to achieve several milestones including submitting the reports to the Regional Board for comment on the several studies the board currently has under review.
The city is expected to address the technical comments discussed by March 18, 2013.