Construction of sanitary sewers began in Fremont County before the turn of the century.  These systems discharged directly into the Arkansas River.  By the end of 1910, complete sanitary sewerage systems were in place in south Cañon, the old part of Cañon City and Florence and are still in service today

In 1953, the Cañon Metropolitan Sanitation District was formed, and the first wastewater treatment plants were constructed in Cañon City and Florence.  Interceptor sanitary sewer systems were constructed that transferred waste water to the treatment plants before discharging into the river.

In 1963, the East Cañon Sanitation District was formed.  They constructed sanitary sewers and a wastewater treatment plant to service the then rapidly growing town of East Cañon.  The Florence Sanitation District was also formed in the 1960’s.

In 1972, the Lincoln Park Sanitation District was formed. Sanitary sewers were constructed to serve an area roughly described as being north of Sand Creek and east of 12th Street.  Lagoons, which are still owned by the district, were constructed east of McKenzie at the end of McCumber Lane.

Later in 1972, legislation was passed that would require upgrading all existing sewage treatment plants. The Federal Water Pollution Control Act Amendments of 1972 (Public Law 92-500) was passed by Congress with the lofty goal of eliminating the discharge of contaminants into the nation's waters by 1985.  This law specified that treatment plants had to meet certain effluent standards by 1983.  None of the existing plants in this area were meeting these new effluent standards. The Cañon City plant was already over capacity and had a facilities study was underway.  The East Cañon plant was nearing capacity.  The Colorado Department of Health placed a moratorium on issuance of building permits in East Cañon until they could show that they were trying to get things resolved and had threatened a moratorium on issuing new permits in Cañon City, but the latter was never implemented.

In 1975, a steering committee was formed to determine if it was feasible to construct a regional facility. Studies were performed, pursuant to federal cost sharing facilities grant, and it was determined that a regional facility was indeed feasible.

In 1979, the Eastern Fremont County Metropolitan Sewage Disposal District was formed which was a joined effort by the four districts: Cañon City, East Cañon, Florence and Lincoln Park and included the systems for the prisons in our county.  This new district began construction of a wastewater treatment plant with a 13 mile interceptor from the plant to 11th street in Cañon.  On April 23, 1983, the Rainbow Park Regional Wastewater Treatment Plant began operation.  The plant has met all effluent standards imposed on it since opening day.  As the final stages of work were being completed, the various boards independently and then collectively decided that it no longer made sense to have a regional authority comprised of the four member districts. It would make more sense economically to consolidate the four member districts into a single entity. Work began in earnest on the concept of consolidation in 1982 and early in 1983.

By the fall of 1984 all legal and financial issues had been resolved and the consolidation issue was presented to the voters who overwhelmingly approved the consolidation. The following month the voters approved a $3.5 million bond issue so the outstanding debt of the regional authority could be refunded and then disbanded, turning over all assets to the new Fremont Sanitation District.