LOCKPORT – Results of DNA tests on bacteria in the water of off Olcott were supposed to solve the mystery of what’s causing Krull Park Beach to be closed frequently each summer.
But the newest results from the state Health Department laboratory haven’t pinpointed the source of the E. coli bacteria.
“It makes things a lot more complicated,” Niagara County Environmental Health Director James J. Devald said Thursday.
The test results from water samples taken in late August just off the beach and at the mouth of Eighteen Mile Creek, just west of the beach, showed the source of the bacteria in the water was geese and ruminants.
Ruminants are a type of animal that chews its cud.
More detailed results on the ruminant DNA showed the source was not cows, Devald said.
That means that agricultural runoff, rainwater washing into the creek from farm fields spread with cow manure, is not to blame for the E. coli problem at the lakefront beach.
“In our mind, it rules out most of it,” Devald said.
Previous tests had ruled out a human source, such as the City of Lockport wastewater treatment plant, which discharges into the creek.
A hypothesis that heavy coatings of seagull droppings on piers near the beach was the cause also has been ruled out.
Other types of ruminants are deer, goats and sheep, but Devald said he doesn’t think any great numbers of those animals are to be found along the creek.
This summer’s test did confirm a 2012 DNA finding that pointed to ruminants.
The county Health Department has been trying to figure out the source of the problem as routine water testing that often shows higher readings of E. coli than are regarded as safe for swimmers.
In 2011, Krull Park Beach was closed to swimming eight times, for a total of 20 days.
In 2012, there were three closings for a total of seven days, and this summer, four closings that totaled seven days.
The Eighteen Mile Creek corridor, running about 14 miles from Olcott to the City of Lockport, is a federal Superfund site because of chemicals blamed on industrial pollution in Lockport.
Devald said he plans for the experiments to continue next year.
“We’ve put in a request to do some more samples,” he said.