Iron and arsenic levels in the Oxford Township water supply will undergo reductions beginning late next year thanks to a method known as “media filtration.”
Township officials last week voted unanimously to authorize Rowe Engineering, Inc. to design a water treatment plant utilizing a media filtration system.
In July, officials gave Rowe the go-ahead to design the township’s first-ever water treatment facility to be located at the Oxford Woods subdivision underground well field. The purpose of the plant, which is expected to be completed by late fall 2004, is to reduce the levels of iron and arsenic in township water.
Media filtration is a treatment method by which water is passed through a particular type of sand to reduce its impurity levels, according to township engineer Shannon Parry.
Pilot testing conducted by Rowe in July “indicated that (media) filtration is effective for removal of both iron and arsenic from the water,” Parry wrote in a Sept. 16 memo to the board.
Parry indicated the objectives of the test were to remove iron levels to less than 0.3 milligrams per liter (mg/l) and arsenic levels to below 10 micrograms/liter.
“The 0.3 mg/l iron concentration is recognized as the level at which higher amounts can result in the aesthetic problems of discoloration and staining,” Parry’s memo stated. “The 10 (micrograms per liter) arsenic concentration will be the maximum allowable (under new federal standards) after January 2006.”
“Pilot testing suggested filtration following the addition of chlorine reduces the iron concentration to less than 0.1 mg/l and arsenic to less than 5 (micrograms per liter), both well within the objectives established,” Parry wrote.
Besides being successful in the pilot testing, media filtration was recommended for a variety of other reasons.
“It’s the most simple, the least expensive and the least operator intensive,” Parry said.
In her memo, Parry noted that media filtration “has been used in the area for iron removal for dozens of years.”
It was noted that media filtration does not soften water or remove volatile organic compounds.
However, neither of those were part of the objectives for the proposed water treatment plant.
With an eye toward the future, township officials also authorized Rowe to design a filtration treatment plant “with the provisions that softening could be added in the future inside the building and aeration (a process used to remove volatile organic compounds) added in the future outside the building.”
Supervisor Bill Dunn said the need for water softening will become an issue only “if the people demand it” and as for the removal of volatile organic compounds, “it’s not an issue now.”
“We’ll probably never need aeration because we don’t have any volatile compounds and we don’t expect to because our wellhead protection plan helps us keep an eye on the groundwater,” he said. “If anything is ever detected through sampling, we’ll have plenty of time for remediation.”