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Success Stories

Mammoth Spring Wastewater Treatment Plant Improvements

Karen Petrus

Outline Of Need:

The City of Mammoth Spring is located in North Central Arkansas in Fulton County. They own and operate a public wastewater treatment facility. The City is positioned on a bluff overlooking the Spring River. The original wastewater treatment collection and treatment system was constructed in 1970. The construction consisted of a typical aeration lagoon followed by a facultative lagoon, followed by a settling lagoon, and thence to the chlorine contact chamber. The city updated the system in 1985 adding a bar screen, new aeration equipment, sand filter, poster aeration, and UV system. The collection system is gravity with pump stations and force mains. There are currently 408 users on the wastewater system.


The wastewater treatment facility has been in service for over 40 years with the last major upgrade 23 years ago. Due to the age of the system and increasing regulations requiring cleaner effluent of water the City has had issues meeting permit effluent requirements set forth by Arkansas Department of Environmental Quality (ADEQ). As a result of this the City has been placed under a Consent Administrative Order for permit violations.

How Rural Development Helped:

Rural Development provided funding for the wastewater treatment facility improvements consisting of replacing the existing treatment facility with a new activated sludge process including the installation of SBR equipment. The new facility would repurpose the existing lagoons to an equalization basin and a sludge holding pond. The UV system would be left as is and the post aeration basin would have new aeration equipment installed.


The Results:

The planned construction of the new treatment facility will allow the City and the wastewater treatment plant to properly treat its wastewater and prevent continual violations of the City’s effluent limitations which can impact water quality with pollutants.


Obligation Amount:
$474,000 WEP Loan and $471,000 WEP Grant
Year(s) of Obligation:
Congressional District:
  • Arkansas: District 1