Riverside’s Water Chromium is 20 Times Lower Than MCL
Riverside, Calif. – “Riverside Public Utilities’ (RPU) water has levels of total chromium that are significantly less than the state and federal Maximum Contaminant Levels (MCLs),” said RPU General Manager David H. Wright.
In fact, as cited in the RPU 2009 Water Quality Report, Riverside’s water averaged 2.0 parts per billion (ppb) for chromium 6, with a testing range of 1.6 to 2.3 ppb during system-wide tests in 2009. “That is much lower than the California MCL of 50 ppb and the federal MCL of 100 ppb,” Wright said.
There is currently no separate state or federal MCL solely for hexavalent chromium, one of two types of chromium typically found in water. A Washington D.C. lobbying group, which is pushing for stricter hexavalent chromium guidelines, listed Riverside’s water in a recent report among 35 systems tested.
“While many water providers are well within the enforceable state and federal guidelines for total chromium, the proposed state guidelines that deal specifically with hexavalent chromium are a unique challenge for California water agencies,” said David H. Wright, General Manager of Riverside Public Utilities.
One of the reasons is that chromium, including hexavalent chromium, is naturally occurring and has shown up for centuries in groundwater supplies like those Riverside relies on. Most water agencies in California’s Inland Empire region report MCLs’ for total chromium in the 1-3 ppb range. Another reason is that regulatory tests can’t currently detect the chemical at a level below 1 ppb.
The new California public health goal for hexavalent chromium is proposed to be 0.06 parts per billion, a substantial shift in the regulation of this chemical. While not enforceable, a public health goal is used to determine the enforceable maximum contaminant level (MCL) for a chemical, which is enforceable.
The proposed public health goal from the state Environmental Protection Agency represents a dramatic increase in efforts to regulate hexavalent chromium, which also is known as chromium 6 or CR VI. However, according to the state EPA, the public health goal is not a boundary line between a “safe” and “unsafe” level in drinking water.
The public health goal seeks to establish a level that would not cause significant health effects after drinking two liters of water with that level of chromium 6 over a 70-year period. A public health goal does not take into account such factors as the cost of treating all water to that standard or the technological limits in reaching that standard. The maximum contaminant level is enforceable and does take into account other factors, such as economics.
“The bottom line information for our customers is that Riverside’s water, is reliable, safe, and meets or surpasses all state and federal drinking water quality standards,” Wright said.