Nestle, the Stamford, Conn.-based owner of the Poland Spring brand, has increased the frequency of its quality control testing following a spike in consumer complaints traced to a bacteria in Poland Spring water.

The bacteria, which affected water in three- and five-gallon containers bottled at Nestle’s Framingham, Mass., plant, poses no human health risk, say Nestle executives and town health officials.

“This was aesthetic only and was not of any health concern,” said Nestle spokeswoman Jane Lazgin.  “It’s safe to drink, and is only affecting a small number of bottles.”

The bacteria did, however, cause odor and taste problems that resulted in 3,500 consumer complaints through May, said Lazgin.

Nestle traced the issues to heterotrophic plate count bacteria, which Nestle officials say is frequently found in water and on other foods, and is harmless.

Lazgin said the contamination originated at the Framingham facility, possibly from water used to clean bottles. The bacteria was not in the water when it shipped from Maine, said Lazgin.

Kevin Mathews, Nestle director of health and environmental affairs, said the company has increased testing for the bacteria and has been “monitoring bottle washers and the temperature of rinse water.”

“It’s those internal controls that we use as the barometer of how well we are monitoring the problem,” he said.

Lazgin said Nestle made other changes.

“We made some adjustments to the sanitizing process and began to purify the water that is used to rinse the bottles,” she said.

Lazgin said consumer complaints have been decreasing.

Although some consumers claimed to have been made sick by drinking the water, Mathews said Nestle’s testing indicated nothing harmful was in it.

“We couldn’t find anything in any samples … that would create or cause illness,” he said.

Ethan Mascoop, public health director for the town of Framingham, said it’s too early to determine if Nestle’s changes and improved quality control measures have had an impact.

He added that there were “no emergency health issues” with the bacteria.

Lazgin said the company started receiving consumer complaints in early 2011.

“At the beginning of this year we saw a trend of consumers calling and complaining about a funny taste or odor,” she said.