Pushed by public health concerns and pressure from environmental advocates, the Environmental Protection Agency is expected to move forward in 2013 with more stringent regulations related to inorganic and organic contaminants in drinking water. Those regulations likely will drive engineering and construction projects at municipal drinking-water plants, industry sources say.

"I think what the future holds is a lot of additional treatment to deal with regulations we see on the horizon," says Tim Worley, executive director of the American Water Works Association's (AWWA) California-Nevada region, which held a conference on inorganic contaminants on Feb. 5-6 in Sacramento. Some inorganic contaminants, such as perchlorate, that are likely to be regulated in the near future "are very widespread, and depending on how they are regulated and at what level, it's going to affect many, many [drinking-water] utilities," he says.

This summer, the EPA is expected to release a draft "Third Contaminant Candidate List," which comes out every six years as a requirement of the Safe Drinking Water Act. According to AWWA, that list is likely to include nitrosamines, strontium and chlorate. Moreover, the EPA is expected to propose revisions to its long-term lead and copper rule, which could potentially affect a large number of utilities, according to Alan Roberson, director of federal regulations for the Washington, D.C., office of AWWA. The EPA also is expected to issue a proposed regulation on perchlorate by the end of the year as well as its draft risk-assessment results on Chromium-6. However, final action on Chromium-6 is not expected for a few years, Roberson says. Once the rules become final, utilities will have about only two to three years to comply, Roberson says. The industry should expect to see a "push by EPA to get a lot of regulations out the door" by the end of the second Obama term in 2016, he says.

The costs of treating drinking water to meet the expected new standards are projected to be "in the billions of dollars," says Jeff Pitenich, vice president and technology director for Walnut Creek, Calif.-based Brown and Caldwell.

Technologies used to treat different contaminants vary depending on the contaminant, water quality, site conditions and location, firms say. "It's very site-specific," says Chad Seidel, manager of water technology at Pasadena, Calif.-based Jacobs Engineering Group Inc. Several well-established technologies exist to treat inorganic contaminants such as Chromium-6, but engineering firms and utilities continually push the envelope to drive down treatment costs. Forexample, ion exchange, reduction coagulation filtration processes and reverse osmosis have all been well demonstrated to treat Chromium-6. However, firms are also exploring emerging technologies— such as chemical reductive media orbiological treatment processes—that address multiple contaminants while also cutting down on residual waste streams, Seidel says.

Brown and Caldwell's Pitenich notes that perchlorate is particularly expensive to treat. For a mid- to large-sized utility, treating perchlorate could cost in the range of $10 million to more than $100 million, he says.