Wastewater Treatment Plant

Wastewater Treatment Plant

Wastewater Treatment Plant

The City of Decatur operates a Class III, 3.25 MGD plug flow activated sludge wastewater treatment plant with a design peak flow of 7.1 MGD. Treatment units consist of a grit chamber, a comminuter with bar screen bypass, primary clarifiers, a plug flow activated sludge process, secondary clarifiers, phosphorus removal by polyaluminum chloride flash missing on the effluent end of the aeration tanks, and ultraviolet disinfection. Biosolids undergo auto thermal thermophilic aerobic digestion (ATAD).  The Class A digested biosolids are disposed of through an IDEM marketing and distribution permit.

Proper disposal of household items

You the homeowner play a major part in making sure your wastewater can effectively reach the Decatur Wastewater Treatment Plant and receive proper treatment. You do this by making sure harmful materials do not get flushed or poured down the drains, including fats, oils, grease, rags, disposable wipes, and more. The main culprits of expensive plumbing problems that harm sewer systems and the environment are: 

Fats, oils and grease

Make sure to put your grease in a can, let it cool and throw it away in the trashcan.

Disposable or "flushable" wipes

Even though these wipes are advertised as being "flushable," they have been proven to cause disastrous problems for your home’s plumbing system and the municipal sewer system. These wipes do not break down and end up causing major blockages and back-ups within your plumbing drains and/or may cause blockages and overflows from the sewer system which are very expensive to fix. Keep a trashcan in your bathroom to throw away wipes and other hygiene products.


Flushing medicine can lead to toxic conditions in our rivers, as the municipal wastewater treatment system is not designed to remove medicine from wastewater. This medicine being flushed can lead to toxic conditions in the river and may lead to trace amounts of those chemicals ending up in the drinking water.  Drop off unused medication in the drop box located at:

Decatur Police Department
112 S. 7th Street

Decatur, IN  46733
Phone: 260-724-8646


Decatur obtained a Streamlined Mercury Variance July 1, 2013 and implemented a Pollutant Minimization Program Plan in regards to reducing mercury in wastewater.

The Indiana Dept. of Environmental Management has been working with wastewater treatment plants to increase awareness of potential mercury sources in Indiana communities.  Mercury poisoning can attack the central nervous system in humans, impairing our sight, hearing and the way we function.  Women of child-bearing age and children, especially those under six, are most susceptible. 

The following household items contain mercury, which can be hazardous if misused or improperly disposed of:  fever thermometers (w/ silver colored liquid inside), antiseptic products containing thimerosal or merbromin, fluorescent lights and Mercury vapor bulbs (neon bulbs), dial (not digital) thermostats, blue-lit automotive headlamps, clothes irons with tilt or automatic shut-off, pilot light sensors in gas appliances (stoves, clothes dryers, furnaces, water heaters, space heaters), switches and relays (in some chest freezers, pre-1972 washing machines, sump pumps, electric space heaters, vehicles and farm equipment), barometers and blood pressure gauges with silver liquid inside, pre-1990 latex paint and some oil-based paint, mercuric oxide and some alkaline batteries, and vintage toy drawing screens / maze games.

Items containing mercury should never be broken open, and mercury should never be put in the trash, burned or poured down the drain.

Items containing mercury should be taken to the Adams County Solid Waste District to be safely recycled.

Adams County Solid Waste Management District
3775 N 200 E
Decatur, IN  46733
Phone (260) 724-9971
For more information, visit http://adamscountyswmd.com


Wastewater Plant
Wastewater Plant
Wastewater Building
Wastewater Building


Karey Fuelling


Decatur Biosoil User Information
Mercury Contamination Prevention

Resource Links

Compact Fluorescent Lightbulbs
Number one thing not to flush
Water Quality Education
Will it flush?

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