How Medford Tests Water To Keep Tufts Pool, Wright's Pond Clean

MEDFORD, MA — With the temperature set to soar into the 90s this week there are few things more refreshing to many than the thought of jumping into a swimming pool or local pond. Keeping public cooling areas in Medford — such as Tufts Pool and Wright's Pond — clean and safe requires vigilance and strict adherence to state guidelines for lifeguards and certified pool operators, as well as a helping hand from those utilizing the facilities.

"The most effective way to prevent recreation water illness is to educate the public and lifeguards," Medford Recreation Director Kevin Bailey said. "For Tufts Pool, the public is educated to wear swim diapers for children who are not potty-trained, change diapers in the bathrooms and to take frequent bathroom breaks. During our preseason training with the lifeguard staff, we review our signs posted at the pool to prevent RWIs."

Bailey said Tufts Pool is tested to determine levels of chlorine and pH each day before the pool opens, and every three hours while it is in use. There is also an hourly check of the automated chemical controller in the filter room that continuously monitors chlorine and pH levels.

The Medford Board of Health oversees water testing at Wright's Pond where an outside lab examines levels of bacteria, including e-coli.

Bailey said that since chlorine can evaporate quickly on sunny days, staff will frequently check the tanks to make sure they do not get depleted.

The Centers for Disease Control caused quite a stir two weeks ago when it reported an uptick in cryptosporidiosis — a parasite-borne illness that can cause bouts of "profuse, watery diarrhea" — being contracted in public swimming areas. The cause of the disease is often people going swimming too soon after being sick and spreading the illness to those who swallow infected water. The CDC report said crypto outbreaks increased annually at an average rate of 13 percent.

"Cryptosporidium has been around for a long time," Bailey said. "Parasites such as crypto and giardia are widely known in the aquatics field because of their resistance to chlorine. Massachusetts has, for some time, given specific protocol to prevent crypto and giardia, which can be introduced into the water from fecal matter and vomit. Given their resistance to chlorine, the pool must be closed for a duration of time with an increased chlorine level.

"In addition, lifeguards are taught if they see fecal matter or vomit, the pool needs to be closed immediately. One of our three certified pool operators are then called in to ensure the proper procedures are followed."

The CDC report recommends not swimming, or letting kids swim, until two weeks after diarrhea symptoms have subsided, not swallowing water in swimming areas and washing hands with soap and water after coming into contact with animals or animal waste — alcohol-based sanitizers do not work effectively on crypto.

Bailey said Medford follows the codes Massachusetts sets forth for frequency of chemical testing and chemical ranges. He said he stresses to new staff how pH works with chlorine.

"A lot of people believe chlorine is the only chemical that keeps the pool clean while, in fact, the pH level has an effect on how well the chlorine can oxidize," he said.

He said a lower pH (7.2 or 7.4) allows the chlorine to oxidize and be more effective than when the pH is at a 7.6 or 7.8. Bailey said he also tries to have the chlorine set to a level 2.5 – the Massachusetts-mandated range is between 1.0 to 3.0 – to ensure there is always enough chlorine in the pool.