Water plant’s tracer test begins, so will surcharge

On Tuesday, Sept. 27, Cambria Community Services District staff and consultants were to have started a two-month test tracking how long it takes for treated water to flow from the Sustainable Water Facility to district wells.

And work had begun the same day on the sidewalls of the new Fiscalini water tank.

Meanwhile, district officials also were getting ready for a workshop meeting about potential environmental impacts from the $13 million water-reclamation plant. That workshop on the facility’s draft subsequent environmental impact report (EIR), starts at 9 a.m. Thursday, Oct. 6.

The EIR

During the district board’s Sept. 22 meeting, directors unanimously agreed to extend the deadline for comments on the report; those comments are now due by Oct. 26.

The completed EIR is to be a key part of the district’s application for a San Luis Obispo County permit to modify the project and operate the water-reclamation plant on a permanent basis, rather than for emergencies only.

In May 2014, the county issued the CSD an emergency permit to build the plant, a permit that limits use of what was then called the “Emergency Water Supply” project (EWS) to declared water-shortage/drought emergencies, and only for existing customers.

When the district began to seek a permanent permit for the plant (as was required by the emergency permit), CSD officials rebranded the plant as the Sustainable Water Facility.

A significant change being proposed for the permanent project affects a large holding pond. Whenever the plant was operating, the district had been pumping into the pond brine left over from the treatment process. In the new plan, the pond would hold freshwater — about 6 to 7 million gallons of it — which would then be available as is to supply firefighting aircraft and, after surface-water treatment, as potable or drinking water.

The plant filters and treats a brackish blend of fresh, salt and treated wastewater, then injects it back into the aquifer to flow toward and into the San Simeon Creek wells that provide much of Cambria’s municipal supply.

Highly treated water, especially that produced by reverse osmosis, can be so pure that it’s corrosive to the injection well, other municipal equipment and infrastructure and customers’ plumbing. General Manager Jerry Gruber said the plant’s treatment process includes the addition of calcium carbonate “to provide a protective scale to the pipes and the injection well.”

The rest of the town’s water comes from the Santa Rosa Creek aquifer.

Tracer test

In an email interview Tuesday, Sept. 27, Gruber said of the tracer test that “we are waiting for one minor part to be delivered, and we do anticipate the test starting today.”

In the tests, sodium bromide is added to the treated water before it is injected back into the aquifer. As the tests progresses, water samples are drawn to determine how quickly the tracer water is flowing toward the wells.

Gruber said the minimum “two-month travel time is a requirement for indirect reuse” of recycled water as potable water.

The sodium bromide stays in the water that goes into the wells. Gruber said, “The element does remain at extremely low concentrations. However, it does not result in any changes to the taste, color or viscosity of the water that our customers receive.”

He said the “tracer test in its entirety has been approved by the Division of Drinking Water and deemed completely safe.”

The plant has been operating and functioning for a couple of days a week since earlier this month, but the operation has been in closed-circuit mode, recycling water back through the system, rather than putting the treated water into the town’s water supply.

Once the tracer test begins, the district can add an EWS Facility Operating Charge to customers’ bills. Gruber said crews were to have read the meters Sept. 27 and 28, and the district would begin levying appropriate charges Saturday, Oct. 1.

Those costs, charged only when the plant is operating, are in addition to the EWS water base charge and EWS water usage charge that customers pay bimonthly, along with their usual bills.

This story was originally published September 28, 2016 at 9:33 AM with the headline "Water plant’s tracer test begins, so will surcharge."