April 2022: South County Regional Wastewater Authority Award-Winning Facility

Hello Gilroy! This month I’d like to Spotlight our award-winning South County Regional Wastewater Authority (SCRWA) facility and its Water Reuse Program. Developing and managing drought-resilient water supplies, like increasing our use of recycled water (non-potable water), is necessary as climate change brings the possibility of more prolonged and severe droughts. The cities of Gilroy and Morgan Hill are both working with Valley Water to add purified water (potable water) to our arsenal against the drought, a future plan that can’t start soon enough. SCRWA Programs Manager Saeid Vaziry will be joining me for the next Conversation and Coffee with the Mayor on Saturday, May 7 at 9:30 A.M. in Council Chambers where you are invited for a face-to-face discussion on wastewater treatment and water recycling in our community, a topic that is so important but does not get the attention it deserves. See you on May 7th!

Mayor Marie Blankley, CPA

Saeid Vaziry has been a leader of environmental programs both in the public and private sectors throughout central California. For 17 years he has brought his concepts and leadership to the SCRWA and continues his work to pursue environmental protection while optimizing ratepayer dollars. As the recipient of the Engineering Achievement-of-the-Year Award by California Water Environment Association, he has honored the SCRWA commitment to the environment with his pursuit of programs and projects that not only focus on efficient and effective operation, but do so without ever losing sight of the need for sustainable and environmentally friendly solutions. Mr. Vaziry is a licensed professional engineer in California, has other work-related certifications and a bachelor’s degree in Civil Engineering from California State University in Fresno. He has worked in local governments at the management level for about 30 years and has an additional 10 years of engineering experience in private consulting.

The SCRWA is a joint powers authority established to manage wastewater treatment and water reclamation for the cities of Gilroy and Morgan Hill. It is governed by a five-member board of elected officials, comprised of three Gilroy city councilmembers and two Morgan Hill city councilmembers. The costs to operate the SCRWA facility are shared by the cities of Gilroy and Morgan Hill in a ratio of 60/40, respectively. Gilroy City Administrator Jimmy Forbis serves as the SCRWA General Manager. The facility is operated by Jacobs, a Denver based company, and has a long-established exemplary reputation of outstanding environmental stewardship. Saeid Vaziry, Senior Environmental Engineer for the City of Gilroy, is assigned to SCRWA and oversees Jacobs.

The facility receives and treats wastewater from domestic, commercial and industrial users, and has a successful water recycling program. Water is one of our most precious resources; and increasing the use of recycled water produced by SCRWA for non-potable uses is an important way to conserve Gilroy’s valuable drinking water supplies. A reliable supply of recycled water not only offsets limited potable water but provides a variety of benefits that support the area’s quality of life. In all fairness, it is worthy of note that due simply to the location of the SCRWA facility, Gilroy receives more of the benefit of recycled water from SCRWA than does Morgan Hill. Both cities, however, recognize the importance of water reuse and mutually support efforts to add the potential for purified water access in south county.

The SCRWA facility is held in high regard by California’s regulatory agencies. It has been recognized by the California Water Environment Association and won the prestigious “Overall Plant of The Year” award – ranked best in California! The facility and staff, with a team of 19 employees, have received numerous awards from the Monterey Bay Region of the environmental association including recently “Plant of the Year” in February. This is a prime depiction of great work and professionalism on the part of all the employees that make SCRWA a successful entity.

Clean water is a vital natural resource for the Gilroy-Morgan Hill community and the SCRWA has demonstrated its support for protecting and enhancing the quality of our community’s rivers, streams, lakes, and groundwater by being considered as the top wastewater treatment and water reclamation facility in California. We strive to manage this resource responsibly by utilizing the public’s money wisely.

SCRWA employees make a positive difference in the lives of over 100,000 residents in Gilroy and Morgan Hill communities. Winning numerous awards from the water environmental association attests to years of excellence in operating and maintaining the facility. We will continue providing superior service and use the awards as a catalyst in raising the bar to continue improving our systems and efforts. Our team works well together, strives for a common goal and pursues new projects to make our facility more efficient and safer. I am always impressed by the exceptional work of our employees and their commitment to provide the highest standard of service to the public. Teamwork is the Key!

SCRWA’s treatment plant uses state-of-the-art, fully automated, high-efficiency equipment to save costs and resources. It is a model of energy efficiency and cost-effective operation and uses an advanced treatment process. The facility was built in 1994. Over the last two decades, the facility has gone through significant changes and more significant construction is currently underway with the design of a membrane bioreactor to ensure the system remains reliable with best available technology. Using cutting-edge membrane technology for nutrient removal will provide the plant with higher quality effluent for beneficial reuse. The $82 million project will feature a new headworks and screenings facility, bioreactors, membrane basins, blowers, a chemical feed and storage facility, and a solids handling facility. The new construction, which broke ground in 2021, is scheduled to conclude in 2025. When the work is completed, the facility will treat more water than ever, from the current 8.5 million gallons daily to 11 million gallons daily, allowing for long-term growth in the cities of Gilroy and Morgan Hill.

As waste is a vital natural resource for our communities, the treated wastewater is recycled around the community, the stabilized bio-solid is dewatered by belt filter presses and the byproduct is mixed with green waste and composted off-site. This byproduct is credited to the City of Gilroy’s disposal and recycling values. Water recycling plays a critical role in preserving the city’s long-term potable water supply, and the SCRWA reliably meets the steadily increasing demand for recycled water.

Recycled water is a highly treated wastewater that is permitted and approved for use in a variety of applications in our area, such as agricultural irrigation of food crops by farmers, business parks landscaping, commercial and industrial uses such as power generation facilities, sports fields’ irrigation and keeping city parks and golf courses green. Recycled water is among the most sustainable, environmentally-sound water resource available to users that does not rely on uncertain hydrologic conditions associated with climate change. As the current historic drought continues, the need to expand access to reliable water supplies grows. The ability to conserve one acre-foot of drinking water for every acre-foot of recycled water used is critical to Gilroy’s ability to withstand current and future droughts.

From its inception, the SCRWA has approached water recycling by providing multiple benefits for multiple end users and has planned for treatment, storage, and distribution projects that meet the broadest needs of the community. Recycled water produced by SCRWA meets or exceeds the standards established by the State of California Department of Health Title 22 Code of Regulations. The distribution system consists of two pump stations and a 3 million gallon storage reservoir at the SCRWA facility, two main pipelines approximately 15 miles mainly through Gilroy and most southern portion of the county (one delivers water to farmers south of the plant, and one delivers water northwest through central Gilroy), a booster pump station at Christmas Hill Park and a storage tank at the Eagle Ridge development with 1.5 million gallons capacity. These components work together to provide reliable, pressurized recycled water to users.

Recycled water is a vital part of the city’s water supply portfolio, and in partnership with Valley Water (formerly Santa Clara Valley Water District) the team is aggressively working to expand recycled water use in the South County and implement facilities in an economically viable manner. Examples of system upgrades currently being planned include additional pumping and storage capacity at the SCRWA facility, and new and replacement segments of piping throughout Gilroy that will improve the capacity and reliability of the distribution system. Additional efforts are underway to update the South County Recycled Water Master Plan and assess regional opportunities for water purification.

The recycled water system supported nearly 850 million gallons of water for our communities in 2021, a record year for recycled water production. On an annual average, 38% of the 2.2 billion gallons of wastewater received by the facility was treated and used as recycled water. In comparison, the percentage of flow by the cities of Gilroy and Morgan Hill was 55% and 45%, respectively, and considering this, the amount of water recycled by SCRWA facility nears the entire wastewater flow from the city of Morgan Hill. Additionally, based on the projections in the Gilroy Urban Water Management Plan for the average daily usage, the savings represent approximately 16% of water demand by the two cities in the Llagas sub-basin.

Some clean-water plants become more sustainable by saving energy; others by producing their own. The SCRWA does both. It launched a major capital improvement program that included an upgrade of the aeration system, along with two solar energy projects that added significant generation without big capital investments. Annual electric rate increases from Pacific Gas and Electric (PG&E) were a big motivator. Another was a program that provides rebates for reducing peak loads and overall energy consumption. The SCRWA had land suitable for solar arrays, investigated options for producing electricity and entered into power purchase agreements with a developer to build the system. The advantages included the absence of capital investment and the ability to lock in a rate for the length of the agreement. The solar system includes two arrays. A 190-kW array at the plant entrance powers the influent pump station and, in fact, yields a significant excess, which is sold back to the grid. Another 1-MW array supplies a significant portion of the facility’s power. It’s connected to a 250-kW battery package (Tesla) to supply power when the solar arrays are not generating and to provide backup in case of problems on the utility grid. Both systems are projected to save significant money — an estimated $6.8 million over the 20-year term as opposed to utility power.

The old aeration system, with three mechanical surface aerators in each of two oxidation ditches, was beyond its life expectancy. In researching replacements, operators performed a stress test that revealed the tanks could handle more volume with more efficient aeration. The SCRWA looked at various options before deciding on fine-bubble diffusion, installed hybrid rotary-lobe blowers, two for each ditch to provide redundancy. The blowers deliver air to panel diffusers by way of a custom-designed set of pipes attached to the walls. Monitored by an automated process control system, it uses variable-speed drives on the blowers with automated dissolved oxygen control. The efficiency of fine-bubble aeration exceeded expectations. The aerobic and anoxic sections of the ditches are still served by the old mechanical aerators operating at much lower speeds.

The completed project qualified for a rebate and received $170,119 from PG&E, one of the largest in their program, as they partnered on the project from design through construction and commissioning. Based on power usage reduction of 1.6 million kWh per year, the rebate covered 9 percent of the $2 million project cost. The improvement has not only enhanced the biological treatment process but also is continually saving energy since 2018.