Muskogee began construction of underground sewer collection lines in 1904 before statehood when the population of the city was 7,000. The people voted at that time $200,000 for this work. The city was fairly well covered in three areas with outfalls and laterals as follows: 1. The 'M' Street line serving the residential area east of the M.K.&T. The tracks followed the draw in the general vicinity of 'M' Street to an outfall through an old type Cameron Septic Tank on the banks of Coody Creek. 2. The Main Street line serving the business district and the west side residential area with an outfall through an old type Cameron Septic Tank on the banks of Coody Creek, west of the M.K.&T. tracks. 3. The North Main Street line serving the north industrial area and also a considerable residential district. It also had an outfall through an old style Cameron Septic Tank. The system was completed between the years 1903-1907 and formed the nucleus of the present sewer system which served the City until the advent of statehood in 1907. At that time the City began to greatly increase in population. With the coming of statehood, the legislature provided by statutes for the building of sewers by assessment districts. The result being several sewers constructed in several separate districts within the City.
With the heavy increase in population in 1910, it became obvious that the emptying of the city sewage into Coody Creek created such a nuisance that it could no longer be tolerated. The City employed an engineering consulting firm to study the problem and they recommended plans to cure this situation. The result was a 48 inch outfall sewer was constructed along the north side of Coody Creek to the Arkansas River. The outfall was built in decreasing sizes along the south and west boundary of the City to a point at 40th and West Okmulgee Avenue. This sewer line has been in continuous use since that date. A north outfall sewer line was built in 1916, beginning at a point near the intersection of Howard Street and North Main Street. The line was a 15 inch pipe and increased to an 18 inch, and then to a 21 inch. It flowed in a northerly direction west of the M.K.&T. Railroad and emptied into the Arkansas River at a distance of about two miles from Shawnee Street and approximately 1,400 feet west of the M.K.&T. Bridge. In addition to the above named outfall lines, many other interceptors and main lines were constructed in and around 1916-1920. Many of these are still being used 90 years later. Since the 1910 Coody Creek outfall, many major interceptor lines and pump stations have been constructed to replace many of the main lines in the City that became overloaded. The City population grew from 7,000 in 1904 to over 25,278 in 1910 and in 1930 it was 32,026. To date all sewer lines either flow by gravity to the 48 inch Coody Creek outfall line or they are intercepted by pump stations that pump the sewage to a line that flows by gravity into the 48 inch outfall line. The only exception is the Muskogee Port Sewer Line that was constructed in 1968-69 and is located on the eastside of the City east of the Turnpike. This 30 inch sewer line comes into the sewer plant at the same point as the 48 inch line. The sewage in the Coody Creek outfall line continued to flow into the Arkansas River untreated and generally unnoticed until 1956 when the City approved a municipal bond issue to construct a sewage treatment plant on East Hancock Street. The plant was completed during the year 1957-58. The 1957 plant consisted of two buildings, one of which housed the laboratory, the control room and the lift pumps. The other was the digester control building which controlled sludge sent to the digesters and drying beds. This process was commonly referred to as primary treatment. In primary treatment, sand, grit and the larger solids in the wastewater are separated from the water. Bar screens, settling tanks and skimming devices are most commonly used for this separation. The primary treatment was capable of removing only set table solids or 35% of the pollutant matter from the sewage flow before being sent to the Arkansas River. This treatment satisfied government regulations at that time.
In 1965 the Clean Water Restoration Act was passed by the United States Congress, which required all municipalities to install not less than secondary treatment. This level of treatment generally indicated the removal of not less than 85% of the pollutants from the waste stream. In line with their requirements Oklahoma required that Muskogee and many other municipalities must install secondary treatment works. In 1973 an addition was added to the Muskogee Pollution Control Plant. A completely new operator control building was built to house a multiple hearth incinerator, a heat exchanger and a reactor as a combined heat treatment system. This system took place of the two digesters and gave Muskogee the distinction of being the first plant in the United States to utilize such a system. Two new primaries were also added as well as two new trickling filters with rock media and a new re circulation pump building for the secondary treatment. Secondary treatment is largely a biological process in which the growth of bacteria and other organisms are used to consume most of the waste materials. The wastewater is separated from the solids and disinfected to kill harmful bacteria and released to the Arkansas River. With the completion in 1973, the Muskogee plant had a primary and secondary system. In 1977 the plant was updated with the addition of two flow equalization ponds that cover a 9.5 acre site. Each pond has a holding capacity of 46 million gallons. There was an addition of a third final clarifier in 1982 with a capacity of 330,000 gallons. In 1994, to comply with Federal regulations, the Muskogee Pollution Control Plant was updated with a new system designed by CH2M HILL. The new design called for the removal of the heat-treat system and going back to the anaerobic digester system for proper treatment and disposal of sludge. The two old digesters were rehabilitated with stationary lids and a third digester with a floating cover was added for extra gas storage. The gas produced in the digesters is used to help with the heating of the digesters and keeps down the use of natural gas. The top trickling filter was changed to a sludge storage tank and a new Bio-Tower (trickling filter) was added to take the place of the two old trickling filters. The re circulation pump station was upgraded to handle the new flow needed to keep organisms on the Bio-Tower alive. Chemical enhancement was added to the process to enable the plant to remove up to 95% of the pollutants from the waste stream entering the plant. In 1997 the Muskogee Pollution Control Plant started Phase II, a two year expansion project, designed by CH2M HILL and built by Ideal Construction, to allow for more wastewater to be treated. A new plant lift station was added with a capacity of up to 50 million gallons a day. A new head works building with channels for two mechanical bar screens and one manual bar screen were built to handle up to 22 million gallons a day. Also located in the new head works building is a new de-grit system. There were two new finals of 1.2 million gallons each that allow for more settling time of any suspended solids still in the water.
A new and larger chlorine building was built next to a much larger chlorine contact chamber. The new chlorine contact chamber can hold four times the volume of the old one and give more contact time for the water with chlorine. This expansion has given the Muskogee Pollution Control Plant almost double the treating capacity at 13.7 million gallons a day permitted effluent flow. Along with the new buildings was added computer control and monitoring which make the Muskogee Pollution Control Plant among the most technically, biologically, chemically and mechanically sound trickling filter plant in Oklahoma.
Since 2017, the Muskogee Pollution Control plant has implemented several upgrades starting with the installation of a basket screen and jib crane at the Raw Sewage Pump Station (RSPS) to protect the five new submersible pumps from large debris. New actuators, valves and gates also were replaced at the RSPS. A trio of new plant drain pumps were installed at the plant drain along with new secondary sludge pumps next to the Secondary Clarifiers. Four new Tricking Filter Effluent pumps were installed in the Re circulation Building along with a new flow control valve. The flood in May of 2019 did considerable damage to the plant requiring major repairs to the south Secondary Clarifier and the replacement of much of the electrical equipment in the Chlorine, Re circulation, and Raw Sewage Pump Station Buildings plus replacement of the HVAC system in the Administrative Building. 2020 saw completion of the flood repairs plus the installation of a new SCADA system along with a rehabbed Gravity thickener. 2021 will see the start of upgrades to the Digester Building including replacement of the boilers, pump, heat exchangers, and associated piping.