Algae causes problems for Rangely water plant

Algae is visible on the mesh intake screens at the Rangely Water Treatment Plant. This summer’s algae bloom required staff to pull up to 100 pounds of algae from the screens as often as three times a day. Jen Hill photo

RANGELY | During the last few years the increase in the algae bloom of the White River has been cause for many discussions. Meetings have been held in Meeker and Rangely to seek answers from various tests and experts. While the exact cause of the increasing algae has yet to be determined many of the consequences are making themselves apparent. In addition to the impact of the biology of the river, the algae has also made the summer months exceptionally challenging for the Rangely Water Department.
In the months of June and July, when the algae bloom is at its greatest, it accumulates on the two intake screens at the Rangely Water Treatment Plant. The screens are designed to protect fish and their larvae from being sucked out of the river. In order to accomplish this, the screens are made of a very fine mesh. Unfortunately, this ultra-fine mesh also makes for a great algae catch. According to Rangely Town Manager Peter Brixius, during the height of the algae bloom each screen must be regularly pulled out to have up to 100 pounds of algae stripped off as often as three times a day. The crew at the water plant has taken to calling the massive pieces of algae they pull off the screens “wigs,” a reference to their long, hair-like appearance.
The algae increase has also raised some concerns about potential toxins in the water. Brixius said that the town has decided to begin testing for Cyanotoxins, “as a result of the combination and potential of Cyanobacteria coupled with harmful algae blooms in a warm water stream which can produce a by-product known as Cyanotoxins.” Should the test come back positive the Cyanotoxins can be treated with proper pre- and post-treatment disinfection. The test costs $280, which Brixius says “makes this one of the more expensive parameters that we would seasonally monitor.”
The water treatment plant currently monitors more than 100 chemical, biological and radiological constituents on varying schedules over a three-year period.
“All of the users on the White River must be concerned about water quality, irrigation issues and recreational benefits from Trappers Lake to Rangely and beyond,” said Brixius. He is hopeful that there will be an eventual solution. “The meetings occurring in Meeker, as initiated first by CPW and now set up and organized by Rio Blanco County to help bring the subject matter experts together to identify possible sources of the problem and begin to correct any issues that are manageable, are good first steps. This looks to be a many year solution.”
So far the meetings have identified multiple potential causes for the algae bloom including fertilizer leeching into the river, changes in river hydraulics, incubation of algae in riverside ponds, insecticide applications such as aerial spraying and changes in the flow of the river.
The Rio Blanco County Commissioners have scheduled another meeting on Wednesday, Aug. 30 at the county courthouse at 9 a.m. to discuss the problem.
In the meantime, the Rangely Water Treatment Plant can take a break as the algae bloom slowly disperses with the onset of fall.