In 1906, three sanitary engineers gave a report to the mayor, city council, Washington State Board of Health, King County Medical Society, and the Chicago, Milwaukee and St. Paul Railroad on “the advisability of permitting the construction and operation of a railroad in Cedar Valley.” Concerned about Seattle’s city water supply in the Cedar River Watershed, the officials had requested information about sanitary conditions and potential pollution from the project.
The report outlines the work undertaken to investigate the issue, specifying that “the proposed location of the railroad, as indicated by stakes, has been followed practically from end to end, and the adjacent strips have been examined at such points and to such an extent as seemed desirable or necessary.” The engineers paid “particular attention to the configuration of the ground and to the nature of the soil.”
They determined their main question to be “whether pollution of the surface of the proposed right of way and of the vicinity by the wastes of the human body can be prevented; and, if it cannot wholly be prevented, whether contamination of the river can be guarded against.” This was “by no means a simple matter, for construction involves the introduction of large numbers of men into the watershed, whose wastes must be prevented from reaching the river.”
They found there was not adequate gravel and sand in the area to effectively filter sewage, meaning that efforts must be made to keep all waste away from the water in the first place. The report outlines specific areas where camps could be built on good soil at a distance from the river, and makes detailed recommendations for building and maintaining latrines. Workers would have to follow strict rules about human waste under penalty of dismissal, and the site “in all respects must be under constant competent sanitary inspection and control, far more stringent than, under ordinary conditions, is necessary.”
With those recommendations and cautions, the board had “no hesitation” in saying the project could be done without undue danger to Seattle’s water supply.