A public meeting was held Wednesday, Oct. 7 at the Saltwater Pavilion to hear results from a Bacterial Source Tracking Project to identify sources of fecal pollution in Little Bay.
Making the presentation was Texas A&M University – Corpus Christi Biologist Jeffrey W. Turner, the principal investigator.
Those in attendance thinking Little Bay’s issues, which Turner said do not present an immediate danger to the public, are directly related to the City of Rockport’s Wastewater Treatment Plant, learned something new.
However, Turner noted his top recommendation for remediation of Little Bay’s issues is diverting wastewater effluent “through a larger riparian buffer that terminates into Aransas Bay.”
In his closing remarks, Aransas County Navigation District (ACND) Chairman Malcolm Dieckow said, “There are some problems, but thank the Lord they’re not (the problems Corpus Christi is facing).
“The ACND can’t do this (solve the issue) by itself. If we all work together, we can solve it. It’s not a problem we can’t solve.”
Turner said the study included the use of data previously provided by various local stakeholders.
“We had an issue with elevated bacteria levels, so we had to imagine how bad it was, and what was its sources,” said Turner. “There’s a lot of concern, as well as sensationalism.”
He noted Texas Beach Watch puts up signs which are let down when bacteria levels are too high. The ACND does this at Rockport Beach. The level that is used to determine when the signs are lowered is based limits, which have been used for close to 50 years.
The objectives in the study are:
• Quantify enterococci (traditional Fecal Indicator bacteria, or FIB)
• Determine sources of fecal waste
• Analyze bacterial diversity
Turner noted that enterococci levels alone aren’t always the most accurate, because results can mean different things based on the type bay system one is studying, and humans aren’t the only things that produces enterococci.
“Enterococci is a good indicator in some systems, but not others,” he said.
There were six testing sites, including Tule Lake, the Tule Ditch outfall to Little Bay, a point in Aransas Bay (off Rockport Beach), and three in Little Bay (including two inside the ski basin).
Samples were taken every two weeks. Extra samples were taken after rainfall events.
Turner said in all there were five “dry loading” test days, and two “wet loading” test days during which samples were collected.
He said the measuring of enterococci levels has been used historically as a measure of water quality, with the Environmental Protection Agency (EPA) setting 104 MPN (Most Probably Number) per 100 ml of water, as an acceptable limit.
Turner noted during the “dry” testing that number was in the 140 range, but during “wet” testing it was closer to the 104 acceptable level.
“Those were opposite results than we expected,” he said. “It could be the dilution effect, or it could be the runoff isn’t bad with bacteria.”
Dieckow said, “We still have to drop the (Texas Beach Watch) signs a lot after rain events.”
Turner noted the sampling results from Tule Lake and the Tule outflow were really high, which drove up the average. He also said the Aransas Bay testing site showed the lowest amount of MPN per 100 ml of water.
“Bacteria levels in Tule Lake continuously exceeded the EPA’s water quality standard, but the levels in Little Bay and Aransas Bay only occasionally exceed (the standard),” said Tuner.
In meeting the second objective (determine sources of fecal waste), testing was performed to determine the amount of human, dog, and gull waste in the water.
Turner said “copies” of the human waste gene were present in every sample, but it was low.
“When it rained, it increased,” he said. “And, that is opposite of what we found when just looking at enterococci.”
In all, Turner reported human waste markers were lowest, followed by gull waste. Dog waste was the highest marker.
“We did not see any correlation between enterococci and human waste,” he said.
Turner then compared the markers from Little Bay, to Corpus Christi Bay. In comparison, Corpus Christi Bay showed levels 10 times or more than Little Bay.
“Corpus Christi has a lot bigger problem,” said Turner.
He noted the state has a lot of data collected through the years, but nobody sat down and looked at it and compared the percentage of samples that exceeded the long-used EPA limits.
When someone finally did do that, it showed Aransas County is in the medium range, with areas such a Nueces, Matagorda, and Harris counties showing a much higher percentage of tests not meeting minimum EPA standards (in some cases, three times more than Aransas County).
Turner then addressed the third objective - analyzing bacterial diversity.
“We did not detect a single human marker in Tule Lake, which really shows the Wastewater Treatment Plant is actually doing a good job,” he said.
Jeff Hutt said the city’s water has twice the number of phosphates than normal, and questioned if that matters.
Turner said it does add nutrients, which bacteria likes, but added, “I think it’s giving you a false reading. It’s hard to remove nutrients (compared to removing bacteria) from a treatment plant.
“The bird, human, and gull markers didn’t have any correlation with enterococci. That’s what we look for.”
ACND Harbor Master Keith Barrett asked, “So, is the nutrient load the cause of the problem with fungal blooms?”
Turner responded that it could be the case.
Dieckow noted the samples from Tule showed no indication as the source of human waste, but it did show high enterococci levels.
“There must be a reason for that,” he said. “Could it be septic tanks? It’s coming from somewhere, even though at low levels.”
Turner said trying to “pinpoint the exact source” is difficult.
Dieckow asked, “Did I hear you say bacteria (levels) can go higher due to nutrients?”
Turner answered affirmatively.
Dieckow then said, “So, if we lower nutrients it would lower bacteria levels.”
Hutt asked what is the cause of Corpus Christi Bay’s high recordings, and why it’s so much different than Little Bay’s.
Turner said Corpus Christi’s issues are infrastructure related.
“They have an aging (wastewater) system, which likely has more leaks,” he said.
“When it rains in Corpus Christi, the enterococci levels go high.”
Barrett asked about the effect nutrients off a golf course might have.
Turner said golf courses are notorious for nutrient runoff.
He noted again the numbers shown in the tests from Tule Lake and its outflow into Little Bay were much higher than average, which drove the average from all the sites up, but added, “You have a long way to go (before getting into trouble with the EPA).
When asked if anyone in the state is doing anything to force an update to the dated standards still used by the EPA, Turner said, “It’s very expensive. No state has managed to modernize.”
He reiterated again, “This area is not a hot spot (in the eyes of the EPA).”
Dieckow noted again bacteria levels could be significantly reduced, if nutrient levels can be significantly reduced.
“In general, yes,” said Turner. “But another study would help.”
Rockport Councilman Bob Cunningham brought up the oyster beds placed in Little Bay by the ACND.
“My understanding was that putting them in would significantly reduce (toxins in Little Bay),” he said.
It was noted by ACND officials the oyster beds have helped, and are healthy and growing, but there are other issues, such as turbidity and silting, that affect Little Bay, as well.
One man in the audience asked, “Would diverting Tule Ditch directly to Aransas Bay (be a solution)?”
Turner said in his opinion that would be the best solution.
“It will have to be diverted sooner or later,” he said.
Another person at the meeting asked if increasing circulation in Little Bay will help any bacteria problem.
Turner said yes.
Dieckow said circulation in Little Bay is a big thing.
“What’s coming in has to be able to get out,” he said.
Hutt asked about dredging Little Bay in an effort to help circulation.
“It’s all about money,” said Barrett. “It will cost five times as much to dredge Little Bay (than what it cost us recently to dredge Rockport Harbor).”
After Dieckow made his closing comments, Rockport Public Works Director Mike Donoho noted there is a countywide group, which meets regularly, addressing stormwater, and similar issues that can lead to increases in bacteria in area waters.
Turner’s final comment was, “If there are high nutrient levels in Tule Creek, it could be from the golf course, or the treatment plant.
“I’d first look at the golf course. There’s a tendency to (first) blame wastewater treatment plants.”