Cyanobacteria Alert Issued for Blackey Cove (Moultonborough)

[Biggd]

Originally Posted by John Mercier

A septic system failure would result in fecal contamination that the DES would need to issue an alert on and immediate action would need to be taken.

What causes the blooms is nutrient loading.

Nutrient loading can be the result of nutrients that are trapped in the bottom soils and released during an upwelling (which is why it can happen below the ice), or any time that water is ''stirred'' by either weather or other activities.

Surface run-off is the most noted nutrient loading factor, and can come from a lot longer distance than one might expect, especially during times of heavy and frequent run-off.

In domestic waste water, this would be most often from things like laundry detergent. It contains a lot of whitener (phosphorus)... that maybe overloading the soil around the leach beds... but also may be just running to a grey water system. The soil during heavy and frequent precipitation will ''wash'' the nutrients from the soil.

The same thing happens with our raised garden and container planters, just in a truncated timeline due to the smaller volume of soil/potting medium being able to harbor less.

So it may not be directly related to the lakefront property... the lake front property at one time being the ''last defense''. It may be travelling down our roads and entering through any spot that it can enter a stream, brook, or intermittent run-off point.

We may be just seeing the beginning of the outcome of decades of nutrient loading.

Agreed, and more development means less natural filtration and more nutrient loading.