When Hollister residents in the west and central regions of the city turn on their taps in the next couple months, the water that flows should be of a better quality than it is currently thanks to a new water treatment plant that is expected to go into operation next month. Yet, water quality remains a top issue in the county, especially in San Juan Bautista where high nitrate levels keep residents on high alert.
On June 20, the city sent out a drinking water warning when a water sample from the city’s well system showed nitrate levels of 11.64 milligrams per liter. The maximum contaminant level allowed is 10 milligrams per liter. The alert warned residents that infants and pregnant women shouldn’t consume the water and advised that water bottles were available at city hall for pickup.
City official Matt Orbach advised that pregnant women, infants and people with certain health conditions shouldn’t drink water with high nitrates.
“The water is safe to drink for normal healthy adults,” he said. “The city still has bottled water available for the people listed above, and any other concerned citizens. We also have a reverse osmosis system at city hall where people can fill up their own water containers as often as they want.”
San Juan Bautista was previously cited for violating the nitrate maximum contaminant level in June 2014. The State Water Resources Control Board lifted the compliance order that November.
The most recent test of the system on June 17, 2017 scored 11.23 milligrams per liter for nitrate levels.
The city’s water system, which serves around 700 connections inside and outside city limits, is comprised of two wells. Well Two is the source of the current nitrate level spike and was also the source of the 2014 issue.
“We have three [wells], but the third has had high nitrates for years,” Orbach said. “That’s been offline for quite a while. “We were pursuing a Well Four, but that didn’t work out.”
Well Two is 315 feet deep, which is considered shallow and makes the well susceptible to nitrates, Orbach explained.
“Generally, shallower wells are more susceptible to nitrates, which sink down from the surface,” he said. “Deeper wells are insulated from nitrates by geologic layers that the nitrates cannot penetrate.”
While the city couldn’t pinpoint the cause of the nitrate level spike in Well Two, the Centers for Disease Control and Prevention website said nitrates can naturally occur in surface and groundwater at a level that doesn’t “generally” cause health problems. High levels of nitrate in well water can stem from well location, improper well construction, overuse of chemical fertilizers or the improper disposal of human/animal waste.
A 2010 report on nutrients in ground and surface water by the U.S. Geological Survey found that nitrates were too high in 64 percent of shallow monitoring wells in agricultural and urban areas, according to the EPA website.
San Juan Bautista plans to add two more wells to the system, according to the city. Well Five will replace Well Two, the cause of the recent nitrate level spike. Well Six is an existing well that’s not online yet.
“We’ve done all quality tests on [Well Six],” Orbach said. “It’s like four out of 10 on the nitrates consistently. We’re about to do the pump test on that soon and that should come online sooner than Well Five. We haven’t even drilled the permanent Well Five.”
In addition to the high nitrate levels, San Juan Bautista is also facing a compliance order issued by the state water board in October 2016.
The order stated the city needed a third water source due to a lack of redundancy in the system. If one of the two operating city wells was taken offline, the other lacks the capacity to meet the maximum daily demand of water.
“The common misperception in the community is that there is not enough water, but that is not the case,” Orbach said. “As a matter of fact, groundwater levels have been so high recently that flowing artesian wells have sprung up around several private wells.”
The compliance order also makes things difficult as new developments like Copperleaf, Rancho Vista and Hillside Vistas come online. All three developments will be served by the city water system once the two new wells are finished.
“Once we get the new wells in our system it’ll have the capacity to handle that,” Orbach said. “That’s not an issue, especially with two brand new wells at 500 feet deep, which can do 250 gallons a minute.”
