| Trending: Drinking water treatment no longer just at plant
AWWA Articles

Trending: Drinking water treatment no longer just at plant

By Ann Espinola

Minimizing concentrations of pharmaceuticals in the water supply can be achieved by drinking water utilities partnering with wastewater professionals and pharmaceutical companies – just one example of a growing trend to decentralize water treatment.

“Water treatment doesn’t happen just at the water treatment plant anymore,” said Dave Rexing, Water Quality Research and Development Manager at the Las Vegas Valley Water District, during AWWA’s annual Council Summit last week. “Once we recognize that, we have some very powerful partners to help us do a much better job.”

John Young, a subcommittee member of the Flint Water Interagency Coordinating Committee, outlined the road ahead for Flint, and said the utility’s problems are complex and will take more time to solve than people think.

The three-day summit at the Westin Hotel in Denver brought together about 125 members of the Association’s International Council, Manufacturers/Associates Council, Public Affairs Council, Standards Council, Technical & Educational Council and the Water Utility Council. The council members collaborated on the sector’s most pressing issues.

Young presented a case study on Flint, and Rexing shared a case study from his own utility. The session was moderated by Jeanine Plummer, a principal engineer at Water Quality and Treatment Solutions, who has a PhD in civil engineering. Plummer also provided perspective on some of the issues facing the water sector.

Rexing noted that pharmaceuticals can harm marine life, and many of them have a long life expectancy in the environment. He said they can be manufactured so that they break down quicker, as well as treated at the wastewater plant so that traces are removed before recycling back into the drinking water supply.

“We need to go to our wastewater folks, hold hands with them, and get some removal processes,” Rexing said. “We need to go out even further than that to the pharmaceutical industry and convince them we’re not trying to put them out of business, but organic synthesis is a wonderful, wonderful science and you can synthesize chemicals that will take care of your human ailments and have less of an effect on the environment.”

Rexing said some synthetic chemicals are routinely found in surface water – including meprobamate, DEET, ibuprofen and sucralose. It’s more realistic, he said, to prevent them from getting in the water supply in the first place than to set regulatory levels for pharmaceuticals.

“To do toxicology studies of thousands of different compounds, and then the potential interactions of an almost infinite number of these contaminants … I’m not convinced there’s enough time left on Earth or money in Fort Knox to literally do all that work,” Rexing said.

Rexing’s crowning example of decentralizing the treatment process is LVVWD’s partnership with two of the area’s wastewater plants to use ozone to diminish the prevalence of pharmaceuticals in the water supply.

“Ozone is one of the best oxidizers to eliminate some of these constituents,” Rexing said. “As soon as we found this out, we approached our wastewater people and said, ‘Look at this. Look at what ozone can do.’ We thought they’d never do it, but they did. They said, ‘We know there aren’t any regulations on these contaminants currently, but we know there’s a trend. We know they might be regulated and we want to be progressive.’”

The partnership greatly diminished the presence of pharmaceutical compounds in LVVWD’s water supply.

“Look what happens when you partner and you hold hands with the wastewater industry,” Rexing said. “If you can get an 80 percent removal with ozone in your water treatment plant, and wastewater plants can do the same, you have an overall 95 percent removal rate across the process. We all win.”

Plummer echoed the partnership theme by saying it’s important for utilities to develop trust and cooperation with their customers before problems occur, because they can be difficult to achieve after. She told the story of a distribution water quality issue in which flushing could help correct the situation in the short term for homeowners.

“But because of the lack of trust and the animosity between the homeowners and the utility at the point flushing was recommended, the backlash from the homeowners was, ‘Well, if I’m going to flush, that’s going to use more water and are you going to give me a credit on my bill to pay for this problem that you created that I now have to flush for?’”

During the session, the partnership message also extended to customer premise plumbing issues such as taste and odor, lead service lines and Legionella. Historically, utilities have maintained their responsibility generally stops at or near the property line.

“There are legal issues, and sometimes you have to draw the responsibility line,” Young said. “But outside of legal issues, I think the water industry looks bad drawing a line and saying, ‘This is ours to here, and this is your responsibility to there.’ It’s a partnership between the customer and us. There is treatment we can provide that helps the water quality on the customer side, and there are things the customer can do to help the water quality on our side and their side of the meter. It’s all about public education. We need to emphasize the importance of a partnership with the customer. If we can achieve that, it’s a big plus.”

Young, who worked for 33 years at American Water in numerous technical and managerial positions, including president, is a member of the water quality subcommittee of the Flint Water Interagency Coordinating Committee. The interagency committee brought together a wide range of experts to find long-term solutions to the crisis.

Young noted that 40 percent of Flint’s residents live at or below the poverty line. In addition, the utility doesn’t bill for 62 percent of its purchased water because it’s water lost through leakage, theft and an outdated metering system. All of these community and operating challenges have combined to leave the utility with long-term financial sustainability issues.

“I didn’t know how bad the underinvestment in infrastructure was until I began my system due diligence and asked for the capital program for the last 10 years. I reviewed their historical capital expenditures and they just weren’t there,” Young said. “I could only find one or two quote ‘capital projects’ and they were really just fixing pipes that broke. Flint was a problem looking to happen even if the lead issue didn’t occur.”

While lead levels in Flint have dropped below action levels set by the Lead and Copper Rule, much still needs to be done to ensure the utility’s long-term sustainability.

“Clearly we need to begin an asset management and capital program in Flint,” Young said. “The distribution system needs to be worked on. We need to optimize the storage and we need to get the disinfection right. We have to get the proper staff training, and that’s already underway.”

Meanwhile, Rexing said his utility continues to develop partnerships to tackle other challenges in the sector, including algal blooms and Legionella.

Rexing mentioned that LVVWD became “superficially involved” after Las Vegas hotels were told several years ago by their insurance agents that they had to take steps to prevent Legionella.

“Their agents told them, ‘You will lose your business. Nobody will come to a hotel that has a Legionella outbreak.’ Many large hotels in Las Vegas use chlorine dioxide inside their premises and they have circulatory systems inside their premises, and there has not been an outbreak since then,” Rexing said.

In another example of partnership, Rexing’s utility recently approached local wastewater facilities about the prevalence of algal blooms on Lake Mead. Ferric chloride can reduce levels of phosphate, which can stimulate algal blooms, Rexing said.

“We talked to these folks and said, ‘We know from a regulatory standpoint you don’t have to do this, but you can do us a big favor, and the lake a big favor, if you would up your ferric chloride dose.’ They said yes. Do they have to do that? No. But joining hands with those folks, decentralizing water treatment and getting involved with the wastewater folks, has been very, very beneficial.”

Do you have a story idea for Connections? Contact Ann Espinola at aespinola@awwa.org or at 303-734-3454.