Lead levels high for 1,000s in small NoCo communities

by Jacy Marmaduke, originally posted on December 13, 2016


Northern Colorado water systems have found a relatively reliable way to tackle elevated lead levels in their drinking water, but the solution can come at a steep price for small communities here and across the country.

After regulatory action triggered new controls across Larimer and Weld counties, two Northern Colorado water systems remain out of compliance with the Environmental Protection Agency’s standard for lead in water: Larimer County’s Carter Lake Filter Plant — which treats water for the Central Weld County and Little Thompson water districts that have struggled with high lead levels — and the Weld County town of Platteville, one of the communities that relies on the Carter Lake plant for water treatment.

Carter Lake’s most recently available water quality test from July 2016 yielded a 90th percentile lead value of 22 parts per billion. The 90th percentile value is a measure similar to a median, which means not all homes serviced have high lead levels. Platteville’s July test showed a lead level of 34 parts per billion. Both are well above the EPA standard of 15 parts per billion, which is a regulatory standard, not a public health standard — there’s no “safe” amount of lead in drinking water. New test results are due for both entities early next year.

Long-term exposure to lead can hinder children’s nervous system development and increase the risk of high blood pressure and kidney damage among adults, according to the World Health Organization. One Pew Research Center study found that the national cost benefits of lead hazard prevention far outweigh the costs of the controls.

Lead contamination in drinking water has become a high profile issue since the water quality of Flint, Michigan, gained national attention in 2015. Flint’s 90th percentile value for lead — a figure that indicates whether the majority of an area’s water samples meet the EPA standard — was 25 parts per billion in one fall 2015 survey.

LEAD:  4 million Americans could be drinking toxic water and would never know

Carter Lake has a corrosion control program in place that is lowering lead levels throughout the towns it serves, including Platteville.

 Corrosion control, as it turns out, is the common denominator for Larimer and Weld county lead issues. Of 11 water systems in Larimer and Weld counties that have seen elevated lead levels in their drinking water since 2010, at least eight of them opted for corrosion control treatment to meet the regulatory limit.

Northern Colorado water tends to be soft, which means it tastes better but is more corrosive to pipes. Few, if any, lead service lines remain in Northern Colorado, but lead from older homes’ internal plumbing and soldering can leach into water if it isn’t not treated correctly for corrosion control. The treatment involves adding chemicals to source water to prevent lead from leaching into water from pipes and fixtures. The approach has proved effective for every area system that’s tried it, per state water quality testing results.

There’s a clear theme among the communities and water systems that have higher lead levels. Each one is small, serving fewer than 10,000 people. Each one, until recently, had no corrosion control plan in place. And many of them lack their own water treatment facilities, relying on private entities or co-owned facilities to treat their water.

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