This month, I'd like to offer some clarifications regarding Soquel Creek Water District's approach to developing new water supplies and help reduce any misunderstandings that people may have.
To aid in replenishing the groundwater basin - which is critically over-drafted resulting in seawater intrusion at both ends of our service area - the District developed a Community Water Plan, in collaboration with community members. This plan is our long-term roadmap to water reliability and sustainability. It has been developed to protect our natural resources as well as meet the water needs for current and future generations.
As the District works toward addressing California's mandate of making our groundwater basin sustainable, four water supply options are currently being considered. Each option is currently at a different stage of evaluation and none of them have been implemented yet. The four options to augment our water supply include: (1) developing groundwater replenishment with purified recycled water (2) purchasing treated surface water from the City of Santa Cruz, (3) purchasing desalinated water from Moss Landing, and (4) developing decentralized groundwater recharge with stormwater.
If you stop reading here, the most important point of this month's article is that our perspective and approach is to provide a comprehensive water supply solution that will involve a combination of options. It is likely that a diversified portfolio of water supplies will be needed, not just a single option.
Following is information we'd like our customers to know about the purified water and surface water options that we're evaluating:
It's and not or - diversification leads to resiliency.
We realize many people may focus on just one supply option to try and solve the region's water shortages. We think of surface water and purified water as complimentary supply options, instead of competing options. The District is hoping to maximize surface water transfers as a supplemental water supply source; however, in the "big picture", surface water is not a guaranteed, reliable source of supply. Limits due to future drought conditions, protection of endangered species, and the City of Santa Cruz' own water supply needs may impact the availability of this source for the District. To ensure resiliency, we value and prioritize developing a diversified water portfolio. This includes groundwater replenishment using purified water, which could be paired with purchasing treated surface water when it's available.
While water from the City of Santa Cruz will not be flowing into our pipes this winter, that doesn't mean we aren't actively working on the surface water option. Preliminary studies and water quality data are required by the state before we can serve treated surface water to our customers. Since the chemical characteristics of surface water sources differ from what our traditional groundwater pipes convey, we are currently working on:
- Flushing pipelines: District crews have been flushing pipelines to scour buildup and remove sediment from within the distribution system in the Capitola and Soquel areas that could cause discolored water and release metals when surface water is introduced. We are evaluating ways to zone off one service area as a pilot area, and have already flushed over 23 miles of pipe (approximately 50% of that area).
- Analyzing water quality issues when blending surface water with groundwater: Testing is scheduled to begin in November 2017 and will examine how different pipe materials in our system may react to surface water such as water quality changes or pipe corrosion. Groundwater, asbestos cement, and the galvanized pipe were harvested from the District's distribution system and sent to Virginia Tech laboratory in early October 2017, where scale analysis and jar testing will occur over the next 6 months.
- Meeting with water quality regulators: The District needs to be granted approval from the State Division of Drinking Water to amend our source water permit. With the purchase of treated surface water, the District will no longer be a 'groundwater only supplier. Staff members from the City of Santa Cruz and the District are planning to meet with the Central Coast region state regulators this fall to present the testing efforts and seek guidance on the next steps.
A water purification facility is not a sewage treatment plant.
For the purified water option, the District Board made a decision to solely focus on the use of secondary-treated effluent that is being discharged into Monterey Bay National Marine Sanctuary and purifying it for groundwater recharge. This already-treated water would go through a closed-loop, advanced water purification system that would further treat it with membrane filtration, reverse osmosis, and UV-light. There would be no untreated wastewater involved, nor the need to construct a sewage treatment plant as part of this water purification option. Rather, an advanced water purification facility (AWPF) would need to be built.
There are three potential locations for a water purification facility under consideration.
For the proposed groundwater replenishment project that would use purified recycled water, we are evaluating three potential locations (1) co-locating near our District headquarters office in Soquel (2) co-locating it at the Wastewater Treatment Plant in Santa Cruz or (3) between the Staples office supply store and the County of Santa Cruz Sheriff's office in Live Oak.
And, with November being a traditional month to express gratitude, the District truly appreciates and is thankful for our customers and mid-county residents who care about their water supply and their community. If you have any questions about this month's topic or anything else related to Soquel Creek Water District, feel free to email Melanie Mow Schumacher or call 831-475-8501, ext. 153 for more information.