In the early years of the twentieth century, following the observation of a federal inspector, who, in 1908, claimed that he found Seattle's dairies to be "among the worst I had ever seen," the Department of Health embarked on a vigorous campaign for safe milk. Two city ordinances passed in 1915 set up strict guidelines regarding the pasteurization of milk and the testing of herds for tuberculosis.
Milk inspectors were responsible for patrolling the farms and plants that made up the Seattle "milk-shed," an area extending from Grays Harbor to the Canadian border. The cleanliness of the cattle, methods of production, and employees of each farm were all monitored by department inspectors according to a set of rigorous standards. Inspectors also oversaw the transportation of the product and its final preparation for market in the milk plants. Samples were taken at several different stages of production for analysis in the Health Department's laboratories.
Efforts to get the City to pass an ordinance that would require the pasteurization of all milk repeatedly failed throughout the 1920s. By the mid-1930s, however, it was reported that ninety percent of all the milk sold in Seattle was pasteurized. During the 1940s both the City of Seattle (Ordinance 72174) and King County (Resolution 10939) adopted a complex set of standards which codified grading procedures regarding the production, processing, and distribution of milk and milk products based on national guidelines. Changing ideas about nutrition came full circle in the 1960s when the County, in response to the outcry that met a proposed ordinance that would have banned the sale of raw milk entirely, adopted new standards for certifying the production and sale of raw milk.