One part per billion is often compared to a drop of water in an Olympic-sized swimming pool, so setting the limit at 10 parts per billion would be equivalent to 10 drops of chromium 6 in a 130,000-gallon pool.
Chromium 6 in groundwater in Glendale and other San Fernando Valley cities is a dark legacy of the long-gone aerospace manufacturing industry. The impurity was featured in the Oscar-winning film “Erin Brokovich.”
State health department officials used more than a decade of Glendale research to determine its recommended limit of chromium 6. Currently, the state only limits total chromium, which is a combination of the contaminant and a nutrient called chromium 3, to 50 parts per billion. The federal total chromium limit is 100 parts per billion.
Glendale has spent about $11 million, most of it from public and industry grants, on research into chromium 6 removal methods.
Health department officials had to set the maximum contaminant limit as close to a 2011 public health goal of .02 parts per billion as economically feasible. They have estimated that reducing the limit to 10 parts per billion will cost water agencies statewide $156 million in total.
“The drinking water standard for hexavalent chromium of 10 parts per billion will protect public health while taking into consideration economic and technical feasibility as required by law,” Dr. Ron Chapman, the department of public health’s director, said in a statement.
The department received the 18,000 comments on its draft maximum contaminant limit from individuals, public utilities, environmental activists and others who both supported and opposed the recommendation over about three months.
Follow Brittany Levine on Google+ and on Twitter: @brittanylevine.
Man accused of bank fraud, stealing 99 Cents Only store customer identities
Police seize Samurai swords, bow and arrow from homeless man
Attorneys for city seek dismissal of comfort-women lawsuit