Colorado State Revolving Funded Projects
Colorado Springs Utilities Hanna Ranch Solids Handling and Disposal Facility
Town of Buena Vista's Water System Production, Storage, and Treatment Improvements
City of Ouray's Lagoon Facility and Constructed Wetlands
Colorado Springs Utilities Hanna Ranch Solids Handling and Disposal Facility:
WPCRF Loan Amount: $22,204,270
With the growth of Colorado Springs in the 1990's and improvements to treatment technologies, the volume of biosolids being sent to Colorado Springs Utilities' Hanna Ranch Solids Handling and Disposal Facility in southern El Paso County has grown significantly. The average daily flows of blended sludge increased from 199,000 gallons per day (gpd) in 1992 to 248,000 gpd in 1996.
To keep up with this increase in volume, and plan for the future, the Colorado Springs Utilites/Water Resources Department undertook to add four new anaerobic digesters to the existing set of four, and three new facultative sludge basins to the existing set of six.
The new digesters, pictured here under construction, will be 85 feet in diameter, 37 feet deep on the sidewall, and have a capacity of 209,850 cubic feet each. The facultative sludge basins, shown here in the background, are 5 acres each in surface area, with a depth of 15 feet. Following treatment in the digesters and sludge basins, the biosolids are primarily disposed of, by subsurface injection, on 274 acres of dedicated land disposal area, which is just over 26% of the entire 1,039 acre Hanna Ranch solids handling and disposal facility.
Town of Buena Vista's Water System Production, Storage, and Treatment Improvements
DWRF Loan Amount: $1,300,000
The Town of Buena Vista has historically received its water supply from a collection gallery and a water treatment plant on Cottonwood Creek. The production capacity of the treatment plant has usually been severely limited in the spring by high turbidity. Though the treatment plant's average daily production capacity was just over 600,000 gallons per day, it was limited at times of high turbidity to as little as 80,000 gallons per day. The collection gallery's daily production has averaged around 1 million gallons per day. At times in the summer, water demand in the Town exceeded 2 million gallons per day, thus causing a rationing program to be implemented most summers. These production limitations necessitated additional supply and storage upgrades.
To address these demands, the Town undertook a project to increase its water production and storage capacity. The daily production was increased through the construction of a new infiltration gallery constructed of 580 lineal feet of 12 inch PVC pipe. For the storage need, a 750,000 gallon steel tank was constructed to serve the Town's upper pressure zone. The project was partly financed by a Drinking Water Revolving Fund loan in the amount of $1,300,000, with an interest rate of 4.01%. As a result of the project, in July of 1999, the Town Council was able to lift summertime watering restrictions which had been in place for more than 20 years.
City of Ouray's Lagoon Facility and Constructed Wetlands
WPCRF Loan Amount: $800,000
In 1988, the Ouray Sanitation District was dissolved, and the community's sewer system was taken over by the City of Ouray. The City determined that its existing lagoon facility was inadequate in allowing it to meet its discharge permit requirements and a 300,000 gallon per day facility would be needed. Though the year-round population of the City had remained fairly steady between 600 and 700 persons, during the summer tourist season, the overnight population grew to more than 2,000 persons. In 1992, the City borrowed $800,000 from the Water Pollution Control Revolving Fund at 4.5% to help finance the project.
The Wastewater Treatment Plant funded with the WPCRF loan has been in operation since June of 1993. The capacity of this treatment plant is 360,000 gallons per day. The facility is a combination of lagoons and constructed wetlands. Since the facility has worked so well, the City is currently in the process of amending the hydraulic capacity limits of its state-issued discharge permit to allow flows of up to 490,000 gallons per day. This upgrade is for permitting only and will not require new construction. The City has not had a discharge permit violation since August of 1994.
