Every Wednesday and Thursday Environmental Center technicians and local volunteers are out around the county collecting water samples that are then brought to, and processed, at the Arnold Campus of AACC.  Values are reported as colony forming units of enterococci per 100 ml of water (cfu/100 ml). Enterococci are bacteria found in the gut of warm-blooded animals including humans and birds such as geese and ducks.  High concentrations of enterococci indicate fecal contamination and the possible presence of pathogenic bacteria.  Values below 104 cfu/100 ml are considered safe for swimming.  After rain of more than 0.5 inches Anne Arundel County recommends avoiding contact with water for 48 hours.