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Individual acts impact safety of water supply
MISSISSIPPI STATE – The cumulative effect of many individual bad choices can be as harmful to the water quality in an area as if a major disaster occurred.
Amy Schmidt, water quality specialist with the Mississippi State University Extension Service, said overfertilizing lawns and pouring chemicals into storm drains harm water quality. But dumping unneeded medicines and personal care products into the sewer system can be just as bad.
“Flushing pills down the toilet or pouring unused liquid medicines down the sink may have been acceptable in the past, but we are discovering that these are not desirable disposal methods,” Schmidt said. “Disposing of unused medicines or chemicals in a safe way and encouraging others to do the same can have a positive impact on water quality.”
Schmidt said the U.S. Geological Survey tests the nation’s surface waters and compiles a list of the compounds found. From 1999 to 2000, they tested 139 streams in 30 states, searching for human and veterinary drugs, household chemicals, and agricultural and industrial chemicals.
“They found one or more chemicals in 80 percent of the streams they sampled,” Schmidt said. “Some of the chemicals they found were antibiotics, detergents, insect repellants, hormones and steroids.
“In general, the chemicals were at very low levels that did not exceed existing water quality standards. Still, we don’t know a lot about the human and aquatic health effects of chemicals at these levels,” she said.
Schmidt said some chemicals are dumped straight into storm drains, some are washed by rain off lawns and gardens and into storm drains, and some are flushed down toilets or poured into household drains. These all reach wastewater treatment facilities and later, surface water supplies. Wastewater facilities are not equipped to remove chemicals such as antibiotics and hormones from the water.
“Wastewater treatment facilities are designed to discharge treated waters to a receiving stream. Some chemicals remain in the water through this process,” Schmidt said. “Chemicals in the water supply also can enter surface water through the sludge that results from wastewater treatment.”
This sludge is created by solids that settle out of the waste stream. This material is used as a fertilizer and applied to land. Chemicals in the wastewater can settle into the sludge and be spread on land, where they may be washed back into the water supply.
“The very best way to dispose of unneeded medicines, personal care products and other chemicals is through a community chemical collection event. Once gathered, these items are usually incinerated or otherwise disposed of in a controlled setting,” Schmidt said.
If that disposal option is not available, Schmidt recommended the next best option.
“Put some cat litter or coffee grounds into a milk jug and put the pills, liquid medicine or chemicals inside. Replace the lid, seal it with tape and put it in the regular trash,” she said. “The litter or coffee grounds will prevent anyone from using the pills if they scavenge through the garbage and find them.”
Larry Oldham, Extension soil specialist, said homeowners also unintentionally pollute surface waterways when they overfertilize lawns or apply lawn or pest chemicals incorrectly.
“People are responsible for the land they manage,” Oldham said. “Each small plot of ground is part of a larger area that is part of a watershed.”
A common problem occurs when excess nitrogen and phosphorous fertilizer enters surface water, enriching the water supply. Undesirable plant and algae species feed on these excess nutrients, multiplying rapidly and taking over necessary species. These undesirable plants also can limit the amount of oxygen in the water available to fish.
Oldham said most commercial farmers are careful about protecting watersheds.
“They want to be good environmental stewards, and it makes good economic sense. Fertilizer that goes into the water does not help their plants grow,” Oldham said. “Most farmers are very good at keeping agricultural chemicals contained.”
Homeowners should do the same, even keeping grass clippings out of the gutter and roadways.
Since watersheds drain massive land areas, Oldham cautioned that what happens in one area can have a negative impact elsewhere.
“What happens on the surface will have below-surface effects,” Oldham said. “Because of the nature of soils and geological formations, a problem may not necessarily appear where the product goes into the soil or water supply.”
Schmidt said the MSU Extension Service recently received a $20,000 grant from the Southern Region Water Quality Program to educate the public on safe disposal of expired medical products and personal care chemicals. Funds may also be used to organize some community collection events and equip other communities to stage similar events.