“We’ve got some data that makes it quite clear that we are adding a lot of salt to our water, and it seems to be coming from the water softeners in people’s homes; specifically from the newer homes in the Discovery Bay West area. So now we’re looking at ways to reduce those levels,” said Town Engineer Gregory Harris.
The study, conducted last month, was done at the behest of the regional water quality control board (RWQCB), the agency that grants the town’s water operations permits. The water board renewed the town’s permit in December, but requested that the town develop and maintain a salinity plan as part of a condition of its permit status.
The 14-day trial included samples taken from 11 sites gathered at the same time each day and measured for salt levels. The spots were chosen from houses in the new and old sections of town, at water plants prior to being treated, sites after treatment, at well water locations, and at positions prior to being released into the Delta at Old River.
“The purpose of the study was to determine where the salt is coming from, which is why we took the samples from the different treatment areas.” said Town Manager Virgil Koehne. “Now that we have the results, the bigger question is: how do we solve it?”
State mandates dictate that salinity levels be no more than 500 micro-ohms per centimeter. The new data revealed the Old River site to be nearly in line at 580 micro-ohms, but the other sites were significantly higher.
Discovery Bay West homes were at 2,400 micro-ohms and old Discovery Bay came in at 1,900 micro-ohms. The water flowing into the water treatment plants measured 2,100 micro-ohms, and out of the treatment plant at 1,750 micro-ohms. The numbers clearly show that the highest levels of salt are coming from the newer homes in Discovery Bay; homes that are equipped with water softeners.
But when the state draws attention to salinity, it means more than table salt. The mineral comes in plenty of other forms, such as shampoo, laundry detergent and any food item that comes in a can. Determining how to best remove it will be challenging.
“We’re looking for good practical solutions while thinking of the ratepayers’ pocketbooks,” said Koehne. “A lot of people think the water (drinking) quality out here is awful, but the water softeners use a lot of potassium and salt. There are reverse osmosis products, but those are expensive. So for right now, we’re just keeping an open mind as we look at solving the problem.”
The town will report back to the state in June with the results of its findings as well as a plan for meeting the water board’s salinity guidelines. “They (the state) expect you to come back with a plan – a good honest plan,” said Harris. “If you don’t, they’ll come back and impose a fine. But we’re working on it; we’ll get there.”

