The MDI Water Quality Coalition is conducting an optical brightener study in Stanley Brook. An optical brightener study will provide information about whether the high bacteria counts that plague the brook in the summer months originate from sewage, or comes from other sources such as animal waste.

Optical brighteners are dyes that are added to almost all laundry detergents to make whites appear whiter. They are found in laundry effluent, which goes through the same drains that carry sewage waste from the houses in Seal Harbor. Thus, testing in Stanley Brook for optical brighteners is a way to screen for the presence of wastewater from a sewage or septic source.

On May 17, 2005 7th and 8th grade students planted optical brightener cages in four locations along Stanley Brook. The cages consist of a piece of PVC pipe with unbleached cotton material attached to one end with a hose clamp. The apparatus will be left in the brook for seven days so the unbleached cotton material will have time to absorb any optical brighteners present in the brook.

Optical Brightener Studies are run in parallel with Enterococcus tests. Enterococcus is bacteria that comes from the gut of warm-blooded animals and is associated with swimming illness. Students will be looking for a correlation between optical brighteners and Enterococcus levels in the brook.

Support for this project has been provided by a grant from Healthy Acadia through the Fund for a Healthy Maine and the Maine Healthy Coastal Beaches Program.