The decision to pour sewage from Seattle’s growing population off West Point beach below Magnolia Bluff was made more than 100 years ago, springing from Seattle’s growth in the late 1800s and a remarkable individual, Reginald H. Thomson. A hundred years later, strangely, his decision resulted in one of the most significant archeological digs on the West Coast.
In 1884, the visionary engineer Thomson, arrived in Seattle. He had a dream to redesign the city. As city engineer, he leveled Denny Hill to create the Denny Regrade and fill in the muddy tide flats of Elliott Bay. He decided the city would get its water supply from the Cedar River watershed 30 miles away and engineered a way to do it that exists today.
He created the public electricity system, which was to become Seattle City Light, and designed the north-south city avenues to carry traffic into and out of Seattle.
The disposition of sewage in Seattle was one more grand plan. Thomson began what was to become a long history of Seattle sewage treatment.
Thomson had noticed that Lake Union was getting horribly polluted because of raw sewage and that Lake Washington was suffering the same fate from residents along the western edge dumping sewage right into its waters.
As city engineer, he began studies of a plan to move the sewage out of city lakes. In the book he wrote in 1949 with Grant Redford, “That Man Thomson,” he chronicles the studies he directed to find the best location in Puget Sound for dispersal of sewage by tides and currents.
In fall 1904, Thomson hired Fred Dehley, a man who had been educated in seafaring in Sweden. He was directed to study the currents that touched the waterfront anywhere between 2 miles south of Alki Point to 3 miles north of Shilshole Bay. Next, Dehley was to place floats near the shore and to keep records of the hour at which each one floated out to sea and the exact point at which it passed.
From these meticulous studies, Dehley located a short stretch of beach, under the bank of one section of Fort Lawton, where there was always an outflow to the north whether the tide was incoming or outgoing. This was the place Thomson decided the sewer line draining 10 square miles of Seattle should empty — just off West Point beach, in what is now Discovery Park.
The city began a complicated process for getting permission from the U.S. War Department to run the line through Fort Lawton in 1905. After much dealing with the halls of Congress and the war department, permission was granted to run the sewer line through Fort Lawton and the Lake Washington Canal. After the City of Seattle recognized and accepted the act of Congress, Thomson’s plan could finally be realized.
Previous dumping into Lake Union and Lake Washington was abandoned. In 1918, the larger, 12-foot-diameter North Trunk Sewer was completed, running under Fort Lawton through a tunnel, discharging untreated sewage and wastewater into Puget Sound at West Point, often fouling the north beach.
It was not until 1958 that voters approved the establishment of Metro, with powers to address the problem of the untreated sewage. In 1966, Metro’s Primary Treatment plant was completed, and all Metro had to do was simply redirect the raw sewage from the trunk line into its new treatment system.
In 1972, Congress passed the federal Clean Water Act, requiring that effluent meet the conditions set by it. Seattle’s Primary Treatment of sewage had to be upgraded to meet the conditions and further improve the quality of water of Puget Sound. Metro began the upgrade to improve the Waste Water Facility demanded by the Clean Water Act. Another location was sought, but there was no alternative to West Point. In early 1988, the Seattle City Council voted to grant the shoreline permit to expand the treatment plant there.
Thirty years after the building of the Primary Treatment Plant, when secondary treatment was to be added and the plant expanded, Fort Lawton had become Seattle’s Discovery Park. When strong opposition arose from the people who did not want their park further despoiled, compromises were reached, mitigation funds were promised, certain beautification features were agreed upon. Metro started construction, not realizing the surprise that would greet their shovels.
The existence of a rich cultural past of ancestral Duwamish, occupying West Point some 5,000 years earlier, was found during the expansion of the treatment plant quite by accident by geologist Brian Atwater. The find only delayed the building of the new plant, while an eight-week archaeological investigation took place.
The secondary treatment plant is fully functional, the beach has been restored and paths from higher ground in the park lead to beach walks all around the point.
The West Point Lighthouse is automated and preserved as part of the history of the area.
The former Army installation, as well as the Navy housing, is in the process of being turned over to private owners.
The archaeological area was mapped and covered over for its preservation. Should there ever be any more digging at the site it will be conducted with regulations to protect artifacts.
The archeological dig proved the West Point site to be where Duwamish and Suquamish Native Americans camped, fished, hunted and collected the bounty of the forest above — an important historical find. The Burke Museum at the University of Washington is the repository of the artifacts found there.
The natural features of the West Point area have been restored as much as possible, and the large area of the secondary treatment plant has been made as unobtrusive as such a large installation can be.
Yet, many trips each day are made trucking out the treated sewage. The popularity of the beach has grown so much in recent times that a gate is proposed to prevent cars from illegally driving to the area.
The story of the archeological dig is in “Magnolia: Making More Memories: The Legacy of the West Point Dig,” by Dale Forbus Hogle.
DALE FORBUS HOGLE is a board member of the Magnolia Historical Society (www.magnoliahistoricalsociety.org). To comment on this column, write to QAMagNews@nwlink.com.