Eight months after Irene, state environmental and health officials are monitoring Vermont’s lakes and streams for any lingering health or safety hazards in recreational waters.

Due to the magnitude of flooding experienced in many areas of the state, it’s likely that any biological or chemical contaminants that may have been washed in by floodwaters have since been diluted by the sheer volume of those waters.

Test results of water samples taken after Irene, as well as more recent samples from early this month, generally show bacteria to be below levels of concern. Sampling at many of the state’s rivers and lakes will continue throughout the summer swimming season. Swimmers may notice that certain lakes remain discolored by sediment even into the summer, but this is not a health hazard.

There have been no reports of persistent chemical contamination following either the 2011 spring floods or flooding from Irene. Any suspected chemical contamination can be reported 24/7 to the Vermont Spill Team at 802-241-3888 or 800-641-5005. The appearance of an oily sheen or discolored sediment could be an indication of chemical contamination.

Although fish have not been tested, there is no evidence to suggest that fish caught in Vermont waters would have higher levels of contaminants as a result of flooding.

Submerged debris may be the biggest danger at this point. Boaters and swimmers should be on the lookout for physical hazards that may be hidden under the surface of the water. Building materials, boat docks and other objects may have been transported by floodwaters to areas previously clear.

The potential for algae blooms on lakes and ponds could be higher this summer due to the addition of excess nutrients like nitrogen and phosphorus carried by runoff from land. Most algae blooms in Vermont are not harmful, but blue-green algae (cyanobacteria) may produce toxins. Vermonters are encouraged to report blue-green algae sightings this summer to the Health Department at 800-439-8550. For photos and more information, go to www.healthvermont.gov.