If water testing results indicate a bacterial count that exceeds allowable limits, the Concord Board of Health will post a warning sign that reads "Swimming May Cause Illness." Subsequent testing will be performed until the bacterial count has returned to "within normal limits." All warning postings will be removed at that time.
Walden Pond is a state run facility and is inspected by
The Department of Conservation and Recreation (DCR). The phone number for state beach water quality is 617-626-4972, the recording is updated daily.