WASHINGTON - The Environmental Protection Agency proposed Wednesday to reduce the limit for arsenic allowed in drinking water to one-tenth the current standard, which would substantially increase the cost of water in many Nevada systems.
The proposed reduction would decrees the allowed arsenic from 50 parts per billion to 5 parts per billion. The announcement came two weeks after an environmental group, the Natural Resources Defense Council, filed a federal lawsuit to force the White House to allow the agency to propose the long-awaited regulation.
''We will continue to take actions to protect public health by strengthening existing standards when necessary, as we are doing today,'' said Carol Browner, EPA administrator.
According to a 1999 table, 11 out of Carson City's 24 wells would be affected by the new standard. There is no estimate on what the cost would be to reduce the level.
Bob Spellberg of the Gardnerville Ranchos General Improvement District said there is only one well that exceeds the limit, and it is at 8 parts per billion.
Fallon has one of the worst arsenic levels in Nevada with 100 parts per billion, twice the present level. Correcting that problem could cost the town of 8,000 people between $10 million to $20 million.
Arsenic has been found in particularly high concentrations in drinking water across the West, particularly Nevada. An estimated 6,600 water systems nationwide serving at least 22.5 million people would need to upgrade their systems to meet the standard.
''It's certainly a very good start,'' said Erik Olson, a senior lawyer for the environmental group, which advocated an even lower standard of 3 parts per billion. ''If this rule goes final, which we sure hope it will, millions of Americans will have water that is safer to drink and have a lower history of cancer.''
But industry officials warned the new standard could increase household water costs up to $100 a year for customers largely in the rural Southwest and pockets of New England where arsenic levels are highest.
Charles Lawson of the Nevada Rural Water Association said in an earlier interview that lowering the standard to a tenth of its present level could put small water companies in danger.
Lawson said the reduction could cost rural water systems $517 million.
There are 110 community water systems in Nevada, most of which have fewer than 3,300 customers. An estimated 43 percent of those water systems exceed 5 parts per billion, according to a survey prepared for the EPA.
''As far as the impact on small systems, it can be brutal,'' said Doug Marsano, spokesman for The American Water Works Association based in Denver.
EPA is asking for public comments about lowering the standard for 90 days. After reviewing the comments and responding, a final rule could be put in place by early 2001.
If a lower standard is set, large water systems serving 10,000 people or more would have three years to make improvements and smaller systems would have five years. About 95 percent of the systems failing to meet the proposed standard are small systems.
State and federal officials could fine water systems failing to meet a water standard, but that rarely happens. EPA has a revolving loan fund that provides about $1 billion each year in low-interest loans to improve water systems.
Water industry representatives, who agree that the current arsenic standard is too high, will resist lowering it so much. The water works association is pushing for a standard of 10 parts per billion, which would match the World Health Organization.
Researchers working for the water association estimated it would cost $600 million a year to meet an arsenic standard of 10 parts per billion in water, after spending $5 billion on new equipment. The cost would more than double to $1.4 billion per year, after $14 billion in capital costs, to meet a standard of 5 parts per billion, the association said.
Efforts to reduce arsenic drinking water followed a National Academy of Sciences report in 1999 that found arsenic in drinking water causes bladder, lung and skin cancer and might cause kidney and liver cancer.
Arsenic is a naturally occurring element and is found in ground water largely because of minerals dissolving naturally over time as rocks and soils weather.
EPA's current standard, set in 1942, ''does not achieve EPA's goal for public-health protection and therefore requires downward revision as promptly as possible,'' the report said.
On the Net: A U.S. Geological Survey map of counties with high arsenic levels is at http://co.water.usgs.gov/trace/arsenic.