Drainage complaints may be valid if either of two conditions is present:

1. Drainage is blocked so that pooled water has impacted a household sewage treatment system (HSTS)
2. Standing water that has stagnated and become a breeding site for mosquitoes.

Clermont County Public Health can’t take action if pooled water is not impacting an HSTS, or has not become a breeding place for mosquitoes. Public Health does not regulate storm water runoff, discharges from swimming pools, or discharges from sump pumps.

Pooled water can adversely affect an HSTS if it is covering a leach field, or a portion of it since water standing over leach lines can severely reduce the capacity of the system to absorb wastewater. Pooled water covering the discharge pipe of an HSTS could cause a malfunction of the system, or cause sewage to back up into a house. If water is backing up because a drainage way has been blocked, and an HSTS has been affected, Public Health can order the property owner to unblock the drainage way or provide a way for the water to drain.

It takes approximately ten days for mosquito eggs to hatch, therefore pooled water may not be considered a health nuisance until it has stood for at least ten days. Mosquito larvae must be observed before Public Health can take action. If mosquito larvae are found the property owner must either treat or eliminate the standing water.

The owner of a property on which water has pooled and become a mosquito breeding site is responsible for treating or eliminating the pooled water regardless of the source of the water. Clermont County Public Health cannot order someone other than the property owner to treat or eliminate standing water on the property.

Standing water may be treated with a mosquito larvicide. This pesticide is specifically formulated to kill mosquito larvae. A larvicide recommended for home use is called “Mosquito Dunks”. It can be purchased at hardware stores or garden stores and is a small, doughnut-like cake. It is non-toxic and is composed of a bacteria which is lethal only to mosquito and black fly larvae. One cake will treat up to one hundred square feet of surface area and will last up to thirty days if it isn’t washed out during a rain. Treatment with motor oil is against the law.

Neglected swimming pools can be unsightly, but may not be mosquito breeding sites. Green water or scum in a swimming pool is likely due to the presence of algae or duckweed and does not create a health nuisance.

If pooled water is present in a drainage ditch on a county road the Clermont County Engineer may be able to clear the ditch. If there is a problem with a drainage ditch on a township road contact local township officials.

See Vector-borne Disease Control for more information about mosquitoes, mosquito control, and mosquito surveillance.

File a complaint online.