The purpose of this fact sheet is to strongly caution against the use of surface water for drinking purposes. Surface waters include lakes, ponds, streams and some springs.
Diseases commonly transmitted by contaminated surface water include cholera, typhoid and giardiasis.
Some residents and visitors think of New Hampshire as relatively rural and pristine and believe it is safe to use surface water for drinking. These people often are renting lakeside cottages or are camping, hunting or hiking. Regardless of the apparent safety of this practice in the past, drinking from ponds and streams is not safe and the DES strongly cautions against this practice. Even though past bacterial tests for a particular pond or stream may have shown good quality, quick shifts in wind direction coupled with poor sanitary practices of man or feces from passing animals can quickly contaminate any surface water source. This rapid and uncontrollable change is the inherent weakness of a surface water.