Prince William Sound, Alaska, on March 24, 1989, when Exxon Valdez, an oil tanker bound for Long Beach, California, struck Prince William Sound's Bligh Reef and spilled 11 to 38 million US gallons of crude oil. It is considered to be one of the most devastating human-caused environmental disasters. Oil still persists in the sand today, and the deaths of 100,000 to as many as 250,000 seabirds, at least 2,800 sea otters, approximately 12 river otters, 300 harbor seals, 247 bald eagles, and 22 orcas, and an unknown number of salmon and herring have been recorded. Test regularly for temperature, pH, turbidity, trace minerals, salinity, nitrogenous waste, coliforms, total organic compounds. Allows people/researchers to locate ideal locations for things like septic tanks, industrial plants, and also measure the impact these devices have on the surrounding water. Additionally, these tests can be indications of water purity, which can help us decide what water to utilize and which needs purifying.