The levels were discovered in a study done from 1990 to 1993 by the Department of Ecology. E. coli largest fecal coliform E. coli comprises the largest portion of fecal coliform in sewage and animal waste. The bacteria can cause intestinal problems such as diarrhea, gas and other maladies. One virulent strain can cause death, especially in infants and the elderly persons with weakened immune systems. The bacteria are so numerous that sometimes the water in the Chehalis River and many of its tributaries is unsafe to swim in, according to the Grays Harbor Fecal Coliform Total Maximum Daily Load Study completed in 2000.
Ecology says the meandering river carries the bacteria all the way to the harbor.
The threshold for safety is 100 colonies of fecal coliform bacteria per 100 milliliters of water. The bacteria also could be a threat to oyster production in the Harbor. High levels of fecal coliform bacteria can contaminate oysters and prompt the State Department of Health to close shellfish beds. For those whose livelihood is growing oysters, the cleanup is very good news, Howard said. Every source that we can block that will create improved water quality downstream is certainly a step in the right direction.