The existing wastewater treatment system is a result of modifying the original 1956 single cell facultative lagoon by splitting it into two cells and installing a surface aeration system in the first cell. This 1987 retrofit was not very effective due to a number of reasons among them the lack of operating depth, high degree of failure among the motors on the aerators and the sludge build up was causing a problem with the detention time in the second cell. In 1995, the in slopes of the two cells were changed from 7:1 to 3:1 slopes and erosion control blankets were installed. This project was funded through a low interest loan through the Montana State Revolving Fund (SRF) program. In 2000, the City purchased wind powered floating aeration-mixer units (pond doctors) and installed them in both cells.
The facility is a source of locally unacceptable odors at certain times of the year. The variable depth of sludge in the second cell creates pockets of sewage that cannot move or circulate which creates a localized septic condition, which increases the odor problems. This is apparent during the fall and spring turnovers. This problem is further emphasized due to the lack of separation between the lagoon and a developed housing area less than 500 feet north of the lagoon.
In 2001, the City drained the first cell and removed approximately 3 ½-4 feet of sludge that had built up in that cell. This was Phase I of a three phase project. The old surface aerators were re-installed and the first cell was put back into operation. During the spring turn over in 2002, there was still the odor problem. Phase II involved the removal of the sludge from the secondary cell and the addition of a cross dike within the secondary cell to create a second primary (storage) cell along with an improved aeration system.
In 2004, the Phase III project created two (2) 7 acre cells that are 15’ deep and have a subsurface aeration system installed. The improvements include a new aeration building and improved piping to allow flexibility to treat the waste water. This project was funded through a low interest loan through U.S.D.A. Rural Development loan program/TSEP grant program, city funds and a grant from the Fort Peck Housing Authority.