Dust under control, Gold Hill claims
Good-bye water truck. Hello, hay crimping. In pursuit of an effective but less expensive form of dust control, Gold Hill Mesa has changed strategies, and project
developer Bob Willard says it's working.
The process, completed about a week ago on 40 undeveloped acres in the upper mesa area, involves a typically 4-inch deep "weave" of hay and clay for soil stability, followed by drilled grass seeding.
"It's clearly and visibly working better," he said, standing outside during a windy afternoon May 21, and added the belief that matters will continue to improve as the grass grows through the hay-clay cap.
The method is a variation of known landscaping techniques (based on browsing sites on the Internet).
The hay-crimping measure had previously been used on the project's graded-but-unbuilt Filing 2, but such had not been deemed necessary for other areas of the property until a fierce windstorm lifted a cloud of dust from the site over the city in February. In response, Willard first authorized the return of a water truck to spray the loose dirt, but looked for other options based on the truck's cost ($18,000 a month) and concerns about its overall effectiveness (for example, in a high wind, the truck would be useless because the water would blow sideways).
The cost for hay-crimping the 40 acres was $65,000, he said. The water truck remains on call, to add moisture during any dry periods and to help with grass germination, he added. The idea is to keep a temporary vegetated cap in place in those areas until it is time for development to occur there.
One area that still awaits attention is the slope above Fountain Creek - the face of the former tailings dam - south of Highway 24. The crimping/seeding method is not as likely to work there because of the slope, Willard said, but he is considering a strategy that would include heavy equipment shaping the hillside into unpatterned tiers, to prevent winds from gaining force.
Most of the acreage in the northwest part of the property has not been touched yet by the development and so retains its prior vegetation.
In a separate effort aimed at controlling pollution, Gold Hill Mesa has built detention ponds to catch water runoff that might contain tailings, and is working with the Colorado Department of Transportation (CDOT) and city Stormwater Enterprise to plan a demonstration project (groundbreaking possibly next fall) to beautify Fountain creek along the development boundary between about 21st and 14th streets.
The development, covering 210 acres in all, is overseen by the Colorado Health Department because of chemical processes used in long-ago gold-milling, but is not considered toxic enough to have the mill tailings removed (although caps of concrete, paving or "clean" dirt are required as part of a voluntary cleanup plan known by its acronym, VCUP). As recently explained by a Health Department representative, the ultimate solution for Gold Hill's dust is to finish building the subdivision so that all the old tailings will be covered.
Westside Pioneer article