HAVERHILL — It was a quiet Monday afternoon on Plug Pond as temperatures rose to just over 80 degrees. About a dozen children were swimming as parents watched from the shore.

“It’s been nice out today, we rode our bikes here,” Andrea Perreault of Haverhill said. She brought her 10-year-old son Oliver to the beach. “Anything to keep him off the computer.”

Oliver was playing catch in the lake with his friend, while Andrea watched from the shoreline. She was disappointed about the beach closing because of bacteria levels for a few days over the July Fourth holiday. She noted that the swimming area Monday afternoon was less busy than usual since the park just reopened.

“It’s a blessing on a beautiful day,” she said. “You can’t live in fear, and if it wasn’t safe the mayor wouldn’t have opened it” back up.

The next few days look to have good swimming weather as well. Tuesday and Wednesday will be mostly sunny in the upper 80s then there is a slight chance for rain on Thursday, and thunderstorms are likely Friday, according to the National Weather Service.

Last Wednesday, the pond was closed after a water test last Tuesday night showed elevated levels of E. coli bacteria, said Shawn Regan, a spokesman for Mayor James Fiorentini. The bacteria levels prompted city officials to close the park through Saturday afternoon.

“Usually this happens after big rainstorms,” Regan said Wednesday. “We had a lot of rain over the (last) weekend which washed all the bacteria from the roads into the pond.”

Jeremy Greene, of Haverhill, brought his 5-year-old son Oliver to the pond early Monday afternoon. 

“There were three people swimming when we got here,” Greene said. He and his family are avid beachgoers who hold a season pass. Greene likes the quiet family-oriented beach, he said. And his son enjoys building sandcastles.

“I encourage everyone to come here. It seems clean to me,” Greene said. He said they would have been there everyday over the long weekend if it wasn't for the temporary closing.

The beach, open to Haverhill residents only, is used by many children and parents who walk to the pond and use it to escape the heat. It is in operation seven days a week from 10 a.m. to 7 p.m. until the last week of August. Lifeguards are on duty during operating hours.

The city tests the water at least once per week.