Local water taste changes with ebbs and flows of state, federal government regulation
Water quality standards seem to be as fluid as our riverways -- with constant movement and redefinition. Marshall Municipal Utilities, like all other utility companies, is under the regulations of the Environmental Protection Agency and Department of Natural Resources, and must continuously comply with the varying standards.
At the water plant near Malta Bend, where chemical treatments usually take place, MMU has had to decrease pH levels and chlorination levels as a result of the lowered water quality standards put in place by DNR a few years ago.
It's because of those lower chlorination levels that some customers say they've noticed changes in how a glass of water tastes. According to Ginny Ismay, MMU's environmental services director, there can occasionally be a chlorinated taste.
"Usually ... it's not because there's too much chlorine," she said, although that's people's natural assumption. "It's because there's not enough chlorine."
Ismay spent 15 years with DNR prior to her position at MMU. She noted that if chlorine levels get too low for the demand that's there, byproducts start developing -- and those byproducts are what actually cause the taste and odor.
"... You bring your chlorine feed back up a little bit and you get a different byproduct that does not have the taste and odor," she said. "Chlorine can be very toxic to certain aquatic organisms at relatively low levels."
Lately, Missouri has been receiving recognition for its water quality. Recently, the City of Puxico placed third nationwide in the Great American Water Taste Test. Puxico is a two-time winner in the state competition, largely because there is no treatment or chemical additive, according to a press release from Missouri Rural Water Association.
According to the MRWA, the third-place win is the highest recognition Missouri has received so far for its taste.
MMU also boasts a well system, located near Malta Bend. But because it has a higher demand than Puxico -- which has a customer base of 450 -- and the water must be softened, the taste is sometimes affected.
"We do strip iron out of it, and occasionally we get a little manganese," Ismay said. "So that's why we have a full plant up there rather than just pumping it out of the ground and into the distribution system."
On the opposite side of Marshall off of Watermill Road, the Wastewater Department primarily uses biological treatments such as using bugs to eat much of the waste.
Here, the department expects to overhaul its 40-year-old facility this spring. Not only are many of the structures in need of repair, mandates are requiring a remodel of the department's disinfection system.
MMU had several disinfection choices, but ultimately decided on ultraviolet light. This year's disinfection project is expected to cost between $1.2 and $1.5 million.
According to MMU's 2010-2011 annual report, the wastewater treatment plant received its renewed five-year discharge permit in Nov. 2011 from Missouri's DNR. But MMU does seem to be taking proactive strides before DNR's regulations even go into place.
"We looked at using chlorine," Ismay said. "We pretty much ruled out using gas because that's what we had at the water plant" and rules for using chlorine gas become cumbersome with the Federal Risk Management Program.
Officials felt UV was the better choice for disinfecting wastewater before the effluent goes to Salt Fork Creek. The UV will help deactivate bugs in certain times of the year, and officials contend that although they aren't currently required to disinfect year-round, the creek is at swimming standards, even this winter.
A major change to the permit mandates 100 percent of all wastewater be disinfected prior to its discharge of effluent water back into Salt Fork Creek. This new system has to be in place by the end of December 2013. Chief Operator Rick Bailey said a disinfection project instigated the facility upgrades, which are expected to reach $5-6 million. It would eliminate several unnecessary buildings.
"We were looking at funding that and in the process" took note of the many mechanical issues they've dealt with, Bailey said. "We just figured while we were doing the disinfection projects, we would look at seeing what it was going to cost to do some new headworks replacement."
The headworks building sits at the head of the plant and is the first collection point for raw wastewater. In the past, water was pumped from there to a grit chamber for grit removal and sent through a clarification system, where water was then circulated and the sludge was settled. Clear water was sent to the lagoons and any sludge went into the headworks building.
After the 1993 retrofit, two aeration basins were constructed. The same headworks facility is still in use, as well as the grit chamber. The office was built as well as lime silos, sludge holding basins and a flow equalization basin, which catches and navigates rainwater into a 9 million gallon holding tank.
"It can probably hold that for two or three days," Bailey said.
Once the flow decreases it's fed back into the headworks.
The plant was built when Excel was a kill plant, but when Cargill transformed the company into a packaging facility, MMU suddenly had more space than it needed -- dropping from a 7.2 million gallon facility to between 2.5- and 3 million gallons.
"We lost, essentially, a million gallons a day, both water and wastewater," Ismay said, although the utility was able to recover.
Now, the system has too many steps for the current demand, and maintenance costs for the department are expected to drop after this year's project -- savings that could be passed on to consumers.
Other operations at the wastewater plant may not see the same drop though.
Although it may be too soon to speculate on rate changes, MMU officials report they, along with state and federal user groups, are working to minimize the impact of EPA regulations. For customers, an occasional change in the taste of water might be the only effect.
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