Mark Bowman still remembers the first time he and his crew had to clean Arvada’s stormwater system in 2004.

Although the system itself had been in place before he began working for the city in the late 1970s, Bowman said, there were no records that mapped the city’s 215 miles of storm pipe, 26 miles of irrigation pipe, 2,369 storm and irrigation manholes, and 3,634 storm inlets that follows into seven tributaries.

“Not only were we getting high levels of toxins into the creeks, but our storm systems weren’t very efficient,” Bowman said. “We would have grates that were plugged, inlets that were plugged, or pipes that were halfway full of silt. We would pull up to an inlet, where all the water goes in, and it would be full of silt, trash, trash bags and a whole bunch

of other stuff.”

Through the years since, Bowman said, the stormwater system has become cleaner and easier to maintain. While many cities have recognized the importance of other essential city services, he said, they are only beginning to realize the importance of having a functional stormwater system.

“Stormwater is still an emerging industry, so there are still some things that we are getting better at,” John Burke, Westminster city project manager and Colorado Storm Water Council co-chair, said. “We understand more things today than we did 10 years ago, and we’re continually looking for better ways to treat and deal with stormwater as it comes through our municipalities.”

Arvada and Westminster, as do most cities in the state, simply provides a system that collects stormwater and moves it through the city, via pipelines into a waterway, such as a creek.

The nation’s stormwater regulatory guidelines are largely guided by the 1972 Clean Water Act.

It requires municipalities to set water-quality standards for all contaminants in surface waters; makes it unlawful for anyone to discharge pollutants from a point source, into navigable waters, unless a provisional permit is obtained; and funds the construction of sewage treatment plants under the

construction-grants program.

“I think people are beginning to see the importance of stormwater maintenance and how it affects the quality of our streams,” Bowman said. “Thirty years ago, a lot of our creeks and rivers were so polluted throughout the United States, so it’s nice that they’ve finally taken a positive approach to this to try and clean that up and reduce the amount of pollutants that go into creeks. It’s expensive to do so, but I think it’s very important to do so as well.”

Bowman said maintenance is particularly challenging in April, May and June, when sporadic rainstorms can cause debris to back up in the city’s stormwater system.

To prevent pollutants from even entering the system, Bowman and Burke said, Westminster and Arvada spend a lot of time and resources to educate residents about effective ways to eliminate accidental or intentional runoff by providing mailers with water bills or holding training sessions.

Among the suggestions highlighted in its mailers, the city of Arvada routinely asks residents to make car repairs in their garage areas and encourages people to take their vehicles to a car wash to prevent soap phosphates from entering the system.

The presence of soap phosphates and nitrogen in stormwater is an emerging concern for advocates who are pushing for stringent stormwater treatment restrictions and for municipal stormwater divisions that must pay a steep price to either redo the entire system or install treatment facilities.

High levels of nitrogen and phosphorus in waters can produce harmful algal blooms, creating dead zones in water bodies, according to Steve Gunderson, director of the state’s Water Quality Control Division. As a result, dissolved oxygen levels are so low that most aquatic life cannot survive, he said.

The state is considering implementing some form of stormwater-quality regulation, but Burke said more research

should be done.

“These are pollutants of issue,” he said, “but there’s nobody that can say they’re being damaged by phosphorus or nitrogen. We’re potentially going to be spending tens, if not hundreds of thousands, of dollars every year trying to find something that we don’t even know is a problem.”

Bowman said Arvada would most likely have to redo its entire stormwater system, resulting in higher fees to residents, if

regulations were passed.

“I don’t know exactly what our storm infrastructure is valued at,” he said, “but I think to reclaim or begin treating stormwater, you’re looking at millions and millions of dollars to do so and that would just be for the city of Arvada let alone the other cities in the

metro area.”