Alkalinity of stormwater a concern on West Slope

Stormwater in the area of El Dorado Trail near the end of Stage Court in Placerville has tested for high levels of alkaline.

The county has placed a warning sign and temporary caution tape at the site. In addition, a temporary fence has been erected to deter the public from coming into contact with the water.

The water source in question is a seasonal drainage that flows northwest under the El Dorado Trail where it continues in a northerly direction. The tests that have produced pH levels between 12 and 12.8 are located in an overflow area adjacent to the drainage where there is ponding. Field measurements conducted farther down the drainage, approximately 200 feet downstream, have produced pH levels of about 7, which are within the normal range for stormwater runoff.

The source of the higher levels of alkaline in the ponding area is currently being investigated.

— Lake Tahoe News staff report