State officials urge action after fecal bacteria found in Cottonwood Creek

WASILLA — A variety of small steps may lower bacteria in a local creek here to acceptable levels, state officials said.

Officials have known some of the fecal coliform bacteria found in Cottonwood Creek are from human sources along the creek since at least July, according to a Frontiersman article from that time. Other sources of fecal coliform bacteria include livestock, pets, and domestic and wild ducks and geese that live along the creek, according to a draft report referred to as the Total Maximum Daily Load, which opened for public comment Dec. 10, and will remain open until Jan. 30, 2015.

Coliform bacteria are rod-shaped bacteria that occur naturally in soil, water, and human or animal waste. Fecal coliform bacteria are a subset of coliform bacteria present in the intestinal tracks of mammals (including humans) and birds.

In the case of Cottonwood Creek, samples of bacteria from the creek were genetically tested at Oregon State University microbiology department, and species of bacteria from all four potential sources were found, according to Laura Eldred, an Environmental Program Specialist with the Department of Environmental Conservation. What the study doesn’t show is what percentage of the bacteria present come from which source, Eldredge said.

“We have no way of saying that,” she said.

While the bacteria themselves aren’t inherently harmful, a specific strain of one human species of the virus — the notorious E. Coli O157:H7 — can potentially be life-threatening in young children and the elderly, according to the Mayo Clinic website. However, in most cases, fecal coliform bacteria are simply used as a method of indicating the presence and amount of human and animal waste in water, according to Eldred. In general, it is other diseases that make people sick.

“We’re really trying to focus on the positive, like what people can do to reduce the amount of waste in the water,” she said.

Because Cottonwood is heavily used for recreation, including swimming, during the summer months, officials are urging an abundance of caution, Eldred said.

“It’s more of a health concern,” she said. “This is something where, if you went swimming and some of the water got in your mouth, you could face a potential gastrointestinal illness.”

The general population can clean up pet waste and make sure trash is secured in the area. Property owners can check to make sure their septic tanks are adequately maintained, Eldred said. Officials also propose to maintain riparian bank surfaces and monitor water quality into the future, according to the policy.

The proposed DEC draft plan for the creek is based around 134 measurements collected at 10 sites between April 2004 and May 2008, according to the DEC report. The state standard for fecal coliform bacteria in a water supply is 40 fecal coliform bacteria for every 100 milliliters of water. Some sites recorded more serious results than others, though not always for obvious reasons.

For example, the point at which Surrey Road crosses Cottonwood, far downstream from Wasilla’s urban core, recorded an average level of 168.4 fecal coliform bacteria per 100 milliliters of water, or roughly four times the state limit, according to DEC data.

A site upstream from Wasilla’s center, Settlement Avenue, recorded even higher levels, recording a limit 40 times that of the state minimum in August 2004, according to data offered in support of the DEC’s proposed action. However, those readings likely result from a culvert replacement project undertaken by the borough about that time. Officials suspect the fertilizer used for bank restoration and hydroseeding is responsible for higher results there.

Officials collected additional, different samples in 2010 to test what kinds of bacteria were present and where they came from, Eldred said.

While some fecal coliform bacteria are believed to be present in every stream, the levels recorded in Cottonwood are too high, Eldred said.

“Fecal coliform bacteria occurs in all warm-blooded animals,” she said. “There are a number of unregulated sources: bears, mink, moose.”

If the DEC’s proposed action were approved, Cottonwood Creek would join Big Lake and Lake Lucille among the listed impaired waterways in the Mat-Su Borough. Big Lake has been on that list since 2006, for concerns about gasoline, oil and grease. Lake Lucille has been listed since the early 2000s over concerns about oxygen depletion, according to the DEC website.

Some local residents have already taken steps to counteract human impacts on Cottonwood. Catherine Inman, the owner of an environmental consulting firm, has since July worked to coordinate septic tank pumping for residents near the creek, with the help of a $24,000 grant from Alaska Clean Water Actions. Inman has used the money to conduct septic tank outreach for property owners along the creek called Septic Smart. If neighbors coordinate their septic tank efforts, the cost is reduced, and tanks can be pumped more frequently and cheaply because septic companies can hit more than one house on a single trip, Inman said.

Part of the concern is that property owners may not realize they have older septic tanks and leachate fields that predate environmental regulations, she said.

“When these older septic systems were built, there weren’t regulations like ‘keep it 100 feet from drinking water,’” she said. “You dug a pit and you did your best.”

“Usually, legacy and heirloom are such lovely things,” Inman joked.

Some new homeowners face a steep learning curve, Inman said. A new property owner had cut down an inconvenient metal pipe in his backyard, revealing a mysterious hole, which he then tried to fill with gravel. It wasn’t until the toilets in the house began backing up and a septic tank repair company was called that the hole was discovered to be the house’s septic tank, Inman said.

“This kind of education is what my program is all about,” she said.

A new round of grants for identical programs opened Dec. 23, according to a DEC press release. The department awards up to $425,000 to reduce waterways pollution, according to the release. The deadline for the application is 5 p.m. Feb. 9, 2015, according to the release.

More information is available at 1.usa.gov/1xr0rH9.