For several days in July, Spring Lake Beach in Burrillville was closed after being contaminated with a pathogen called shigella.
Ninety-two people were sickened and 16 were hospitalized with symptoms of severe diarrhea.
The NBC 10 I-Team spoke with Health Department officials who said there's no way to test water for shigella. The water was contaminated just on one day, July 4, and by one swimmer.
For public safety, standard water tests look for high levels of bacteria called enterococci. Tests at facilities like Spring Lake should be done at least once a month.
According to the Health Department, bacteria levels cannot exceed 61 colony-forming units (CFU) per 100 milliliters for fresh water beaches.
The I-Team decided to collect water samples at three fresh water beaches in northern Rhode Island.
The first test at Spring Lake showed more than double the standard levels of bacteria in the water. A second test showed lower than standard levels.
At Lincoln Woods, the water just barely made it under the acceptable standard, three points below the Health Department limit.
Governor Notte Park in North Providence was the cleanest. It didn't come close to the standard. The level was 7.2 CFU/mL.
The I-Team also reviewed the testing records at Spring Lake.
The facility has been following Health Department protocol and consistently testing the waters once a month for the past season.
One of the tests was taken days before the outbreak on July 4, and it was clear of bacteria.