While most of Colorado's drinking water is safe, 95 privately operated public drinking-water systems around the state contain arsenic levels that exceed the EPA's new standards, a state audit report released Monday said.
The systems, which include small towns, businesses, mobile-home parks and homeowner associations, get their water from underground wells where arsenic, a highly poisonous metallic element, is found naturally in bedrock formations, said David Holm, head of the state's Water Quality Control Division.
Most of the private systems are found in southern Colorado, he said.
"There's arsenic in groundwater in the San Luis Valley and in the Lower Arkansas River Valley," said Holm. "It's not whether it's dangerous, but at what levels." Holm said that even at low levels arsenic can be carcinogenic.
"The types of effects are long-term effects," Holm said.
The Environmental Protection Agency has proposed tightening the current arsenic standard of 50 parts per billion (ppb) to 5 ppb after evidence accumulated over the years show arsenic is a threat to public safety, said Bob Benson, EPA's Region 8 toxicologist in the drinking-water program.
"The EPA is lowering the standards to make the drinking water safe from what we consider a fairly significant adverse health effect," Benson said.
But Sen. Doug Lamborn, R-Colorado Springs, a member of the audit committee, said that many people are questioning the EPA's new standards. "I have a question as to whether they are realistic or not," he said.
Citizens can comment on the EPA's proposed new standard until Sept. 20. The target date for enacting the new rule is Jan. 1, Benson said.
According to the audit, more than 97 percent of the state's 2,200 public water systems were in compliance with federal drinking-water standards in 1997. In 1998, about 90 percent of the state's streams met standards.
The good news regarding arsenic, Holm said, is that the division now has money to contract with local health agencies, which will look at the management systems and technical capabilities of water operators to comply with all of the requirements of the Safe Drinking Water Act. A public water system is defined as providing water to 25 persons for more than 60 days.
The audit also showed that state water quality inspectors are 44 percent behind in looking at major industrial wastewater permits this year, but noted that the backlog has not hurt the state's water quality.
SOURCE: Denver Post Capitol Bureau