For nearly a century, Golden sent all of its wastewater (sewage and industrial) directly into Clear Creek. This was the standard practice in that era, and other towns along the Creek, both above and below Golden, were doing the same thing.
The Federal government did try to pressure municipalities to treat wastewater, but during the Depression we lacked the funds to do it and during the War we lacked materials and manpower.
Finally, in 1953, Coors built a wastewater treatment plant and agreed to treat Golden's wastewater as well as their own.
73 Years Ago
That background made this article from the November 5, 1953 Colorado Transcript interesting.
Pipeline Will Carry Heating Plant Waste
Installation was begun this week by the Colorado School of Mines of a pipeline from its heating plant at 13th and Cheyenne streets along Cheyenne street to Clear Creek. This pipeline will carry water used to flush and settle ashes at the school’s heating plant. These waste materials have been disposed of through the city’s sanitary sewer system but now that sewage is being treated by the Coors-Golden Sewage Disposal plant, some other method of disposal had to be provided....
Colorado Transcript - November 5, 1953
I wasn't able to track down when they stopped sending this waste to the Creek, but the answer may lie within a 1970 article.
The Clean Air Act was passed in 1970, followed by the Clean Water Act in 1972. One or both of those acts may have been responsible for a change to the heating fuel mentioned in the September 22, 1970 Oredigger (the School of Mines newspaper).
Two new, gas-fired boilers with diesel fuel backups are currently being installed in the CSM heating plant. They will replace the two coal-fired boilers which were installed in 1948 when the plant was first built.... Because of the switch from coal to gas, the plant will be able to cut down on its pollution of the air. According to Bill Hayward. Sales engineer for the Public Service Company of Colorado, ten to thirteen percent of all coal goes into the air as a solid pollutant...
Oredigger - September 22, 1970
That article mentioned air pollution but not water pollution. The "flushed and settled ashes" may have been piped from the heating plant to Clear Creek from 1953 until 1970.
