An alumna of the class of 1972 writes, "Mrs. Richards, the first woman graduate and woman instructor at MIT, pioneered the field of sanitary chemistry in the US, and developed the first map of water pollution by testing chlorine in the waters of Massachusetts.
"Ellen (Swallow) Richard was assistant to Prof Nichols in 1884 in setting up the Institute of Technology's sanitary chemistry laboratory, the first public health laboratory in the US. In 1887, she spent two years developing the first map of water pollution in the US. Mrs. Richards tracked the most significant trace of human activity at the time, chlorine from salt used in food and industry, and developed an "isochlor" map from more than 40,000 samples from around Massachusetts. The first "Standard Methods for the Analysis of Water and Wastewater" published in 1905, based its measure of polluted water against the findings of ESR's base map.