Officials at the Valencia Water Company failed to step up their water sampling after one of its wells revealed a level of nitrate that exceeded the state limit and warranted closer scrutiny.
Nitrates are salts that occur naturally and are used heavily in fertilizers.
Failure to sample water as often as it should have done, however, did not compromise the water quality, a Valencia Water Company official said.
“We are testing it more often now,” Ken Petersen, general manager of the Valencia Water Company told The Signal Thursday.
The State Water Resources Control Board sets a threshold for how much nitrate can be present in drinking water.
And, whenever nitrate levels exceed the allowable limit, the water agency monitoring that content is expected to step up its monitoring.
The Valencia Water Company failed to do that and, as result, informed its customers last month about the “oversight.”
VWC officials should have sampled water in the winter of 2016, and again the following spring, after a July 2016 reading showed nitrate levels slightly above the allowed limit.
Although the water is safe to drink, VWC should have told its customers about the monitoring mistake.
Safe to drink
In a notice sent to VWC customers, Petersen explained: “Due to the monitoring oversight, samples were not collected during the fourth quarter of 2016 and the first quarter of 2017, according to the notice sent to customers.”
Water company officials stressed in their notice that “this did not compromise the water quality” and that quarterly monitoring of the water had begun.
The last sample was collected on May 18, 2017, during the second quarter of 2017.
Before that, company officials collected a nitrate sample from Well W9 on July 21, 2016, which was found to have a concentration of 5.5 milligrams of nitrate per one liter of water, exceeding 50 percent of the maximum contaminant level set for nitrate.
At that point, VWC “should have initiated quarterly nitrate monitoring for Well W9 in the fourth quarter of 2016 and first quarter of 2017” but didn’t.
Petersen said Thursday that the water in Well 9 was “offline,” when the July 2016 sample was taken.
“The water in W9 was never put in the system as a constant source of supply,” he said.
The company’s notice to its customers reads: “Even though this failure was not an emergency, as our customers, you have a right to know what you should do, what happened, and what we did to correct this situation.
“We are required to monitor your drinking water for specific contaminants on a regular basis.
“Results of regular monitoring are an indicator of whether or not our drinking water meets health standards.
‘During the fourth quarter of 2016 and the first quarter of 2017, we did not complete all monitoring requirements for public water systems using groundwater.”
Because of the “oversight” VWC officials were compelled to alert the public about it within 10 days.
State law requires the water retailer to notify school employees, students and parents — if the students are minors, as well as residential rental property owners and managers, including the owners of nursing homes and care facilities who, in turn, would inform their tenants.
Business owners also have to be notified so that they, in turn, can inform their employees.
The nitrate level sampled in May 2016 was only slightly above the legal limit, and only high levels of nitrate in drinking water are associated with adverse health effects.
Nitrates can get into the groundwater through septic systems, discharges from wastewater and agricultural ponds, leaky sewer lines and by farmers applying manure-based fertilizer.
Petersen said he blames local agriculture for levels of nitrate that exceeded the state limit.
“We can blame farmers,” he said, referring to the amount of fertilizer used in agriculture that finds its way into groundwater.
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