TCP, nitrates may cost city $15.7M
September 19, 2019 | View PDF
The city is continuing to investigate different methods to rid its drinking water of contaminants – but drilling new wells is a major possibility, at a cost of over $15.7 million, according to a consultant’s report.
Last year, the city awarded a professional services agreement to Dee Jaspar and Associates, Inc. to prepare an analytical report for a water treatment strategy for the water supply.
At this week’s City Council meeting, Public Works Director Biridiana Bishop said that the city’s water system relies on groundwater provided by six existing wells. “The useful life of a well can be 50-60 years,” Bishop said. “Five of the wells exceed TCP 123 levels and three exceed nitrate levels. The only well that doesn’t need treatment is Well #11.” She also said that the city’s wells are 10 to 20 years old.
According to the report, the recommendation is to drill four replacement wells and treat Well #12 for 123 TCP, Bishop said. “This will be done with the goal of identifying well sites that will not require treatment.”
Other alternatives included in the report were well head treatment, centralized treatment at one location or treatment at multiple locations.
Bishop also reported that the city will be conducting a hydrogeologic study, to analyze how much water is circulated. That is expected to cost $10,000, she said.
“The three wells have exceeded nitrates a few times in their lifespan, but they do not regularly exceed them, and Well #11 has only exceeded the level of nitrates once, so treatment isn’t recommended at that well.”
Bishop said that the city is aware that nitrate treatment may be necessary in the future and is planning accordingly.
“The cost to drill four new wells and treat Well #12 is $15,765,902.68, or $3,436,560.67 per well,” Bishop said. She does not expect the costs of operation and maintenance for the wells to change from currently budgeted levels.
Bishop said that either all four wells could be drilled at the same time or separately, which will delay the completion of the project.
But regulations on permissible contaminants is constantly changing.
Last year, Acting Public Works Director Jeremy Bowman described the situation: “Many contaminants are regulated, but this is the first time 123 TCP levels have been regulated, even though it has been in our drinking water for quite some time.” He said that what was not considered a contaminant level on Monday may be changed to a contaminant level by Tuesday of that same week.
Councilmember Gilberto Reyna asked if new wells would guarantee there would be no more contaminants. “There is no guarantee,” Curtis Skaggs of Dee Jaspar said.
The council and the city attorney met in closed session to discuss “anticipated litigation,” – but no details were released.