Posted: Mon, 5 Dec 2011 08:34 AM - 11,727 Readers
By: Farzad Mashhood
photography by Alberto Martínez
One expert used simple rhyme to explain the reason behind high levels of bacteria in Texas waterways.
"The solution to pollution is dilution."
Increased bacteria levels in rivers and streams due to decreased flow that typically dilutes runoff pollution is an expected yet overlooked toll of the drought, said Andrew Sansom, executive director of the River Systems Institute at Texas State University.
So, without more flow in waterways, there is no solution to pollution.
"We look at this drought as an issue of supply, but the real dark side is that we're facing some real potential water quality issues as well," Sansom said.
A report released Thursday by an environmental advocacy group concluded that bacteria levels are dangerously high in tests on five of 13 water bodies — including three in the Austin area: Barton Springs, Hamilton Pool and Bull Creek near Loop 360. The study compiled available data from 2010 through summer 2011 — kept by the City of Austin, the Lower Colorado River Authority, and other governmental agencies and river authorities — at popular Texas swimming locations .
Insufficient data — fewer than 10 tests in the year and a half — stymied analysis of a dozen more locations, said Luke Metzger , director of Environment Texas Research and Policy Center, which headed the study.
"The fact is that because we're not testing frequently enough, it's quite possible that the water is more unsafe or had more exceedances than we know about," Metzger said.
E. coli sources include runoff from agricultural fields, malfunctioning wastewater treatment systems, landfills, urban sprawl and domestic animal waste, according to the report.
Runoff into waterways is normal, Sansom said, but decreased flow during the drought has made the bacteria appear in higher concentrations.
"We should expect higher levels of all kinds of water quality problems because flows are so low," said Sansom, who used to head the state's Parks and Wildlife Department. "Fifty percent of streams are flowing at 10 percent or less. What that means is the level of contamination will increase because there's so little flow in the streams themselves."
Metzger said state and federal regulators should reduce allowable levels of bacteria in waterways.
"There's just not enough information out there about water quality in some of these popular swimming holes," he said.
He suggested that state regulators such as the Texas Commission on Environmental Quality post real-time water quality data for easy public access, similar to Texas Beach Watch, managed by the General Land Office, which posts real-time beach quality data online.
Data for water quality in many waterways are available on the environmental commission's website, but are hard to find and hard to discern.
The commission cautioned against relying on single measurements of E. coli data.
"In reviewing E. coli data from around the state, it's common for single measurements to exceed criteria in streams and rivers, particularly during periods of rainfall. We recommend that all swimmers use appropriate caution when swimming in untreated water, especially after rainfall," spokesman Terry Clawson said in a statement.
Hamilton Pool is typically closed to swimmers after rain events until tests show bacteria levels are low enough, said Dan Perry, the West district park manager for Travis County who oversees the pool's operations.
Metzger said the survey did not account for whether swimming holes are open to the public when tests show high E. coli levels.
Data compiled for the report from the LCRA show Hamilton Pool's E. coli levels went over the Environmental Protection Agency standard by more than double on June 29, but Travis County monitors showed the levels were well below the standard that day. Neither the researchers nor the county monitors could explain the difference .
Barton Springs Pool had a bad day on Aug. 31, when more than double the EPA's maximum bacteria concentration showed up in a test, Metzger said.
City Parks and Recreation Department officials did not return calls for comment on why the levels were high and whether the pool was closed that day. The pool is usually cleaned on Thursdays.
Bull Creek near Bull Creek District Park showed up as the worst offender, exceeding the state standard in 35 percent of tests and the higher federal standard in 47 percent of tests, but Metzger said much of that is due to animal waste from the park.
The Austin Parks and Recreation Department closed the popular off-leash area at the park in 2009 after tests found high levels of bacteria in the creek, which city officials attributed to dog waste.
