31.   The researchers first analyzed lake water samples for levels of phosphorus, which is found in sewage and acts as a nutrient for algae.

32.   The water samples Kling and Bettez are taking will be broken down chemically to yield a precise reading of the carbon content of the water.

33.   Thermal photographs taken by the pilot allow scientists to identify algae blooms and other irregularities, and Baywatch volunteers then collect water samples and readings for laboratory analysis.

34.   To keep track of water quality, municipal workers collect dozens of water samples, seven days a week from all five boroughs, for analysis in the lab.

35.   Traces of explosive chemicals, including TNT, were also found in the water samples, taken from an area near where World War II munitions were manufactured.

36.   Water samples and fish must be collected immediately.

37.   We are running a number of tests on water samples.

38.   Water samples from the bowl analyzed by an Los Angeles Police Department chemist indicated that a lot of cocaine was dumped into it, he said.

39.   Water samples show similar chemicals at other dry-cleaner locations in town.

40.   Water samples are taken every other week, Ms. Fallon said, and by March the team should have enough data to see if the project is working.