Beaches clear of swimming advisories ahead of warm weekend

LACONIA — Bacteria advisories on Lake Opechee, Bond Beach and at Weirs Beach have been lifted, Laconia Parks & Recreation staff said Thursday morning. 

Test results returned Thursday morning showed fecal bacteria levels below the New Hampshire Department of Environmental Services standards, so the advisories were lifted. 

When a bacteria advisory is issued for a beach, it doesn’t close it, but is meant to serve as a warning against potential health risks.

A clean sample is defined by a bacteria result lower than 88 parts per 100 mL, the state benchmark, according to NHDES staff.

If two sample results from one location are above the state standard, or if any one sample is above 158 parts per 100 mL, an advisory is issued. When a beach is under an advisory, signs are posted at entrances. Signs are removed when sample results indicate bacteria levels below the state standard. 

NHDES staff don't test Laconia beaches as part of their state program, but the city's Parks & Rec Department does. The best way to know if any city beaches have active fecal bacteria advisories in place is to call that department at 603-524-5046 and ask.

That’s the case for numerous cities and towns throughout New Hampshire. The locations sampled by NHDES staff are displayed on the Healthy Swimming Mapper, which also notes locations where cyanobacteria blooms have been reported, and where cyanobacteria watches and warnings have been issued. 

Consult the Healthy Swimming Mapper by navigating to des.nh.gov/water/healthy-swimming/healthy-swimming-mapper.

In other news, there were no cyanobacteria warnings or watches in the Lakes Region as of Thursday afternoon, though a cyanobacteria warning remained in place on Province Lake in Effingham and Wakefield. That warning was issued on Aug. 13.

There were, however, several cyanobacteria reports on Lake Winnipesaukee, mostly concentrated in the area of Long Island and Moultonborough Neck, headed into the weekend. 

In three locations near Moultonborough Neck, reported cyanobacteria blooms were tested and, according to the Healthy Swimming Mapper, results showed cyanobacteria cell density in excess of 70,000 cells per mL, the state benchmark.

Those reports were made on July 22, and Aug. 13, respectively. 

A cyanobacteria warning is issued on a waterbody when samples exceed 70,000 cells per mL at multiple locations. A watch may be issued based only on a photograph, when the cyanobacteria density is approaching 70,000 cells per mL, when only one sample exceeds 70,000 cells per mL, or when the bloom material has passed. 

Warnings do not close a body of water to recreation, but DES staff advise to avoid activities near visible bloom material. Cyanobacteria material grows lake-wide, and accumulates on the shoreline due to wind, wave and boat action. The whole waterbody may not be simultaneously affected, but material can move around to various parts of the lake.

When a warning is issued, resampling is performed weekly until a bloom subsides, according to DES staff. Warnings are issued between May 15 and Oct. 15.

Temperatures in Laconia are predicted to reach into the mid-80s this weekend, after a cool week.