Brightening the Duwamish's Future

In 1906, the Duwamish River curved and twisted through the mudflats of Seattle. Ten years later, like a string pulled taut, it was nearly straight. Now ships could move cargo easily from Elliott Bay to industries along the Duwamish "waterway," no longer a river even in name. The former loops, or oxbows, were filled with mud dredged from the channel, leaving stubby protrusions, like branches cut off near the trunk. These became slips for barges to moor while being loaded and unloaded.

The river was channelized to promote economic growth and that goal was met. Meat packing plants, dairies and sawmills perched on the banks and dumped wastes in the water. They gave way to steel mills, airplane and truck factories, asphalt plants and barrel recyclers. Old, new channels of Duwamish RiverThe waterway received wastes from all of them. The residents of Seattle sent their waste there, too. Sewage and stormwater flowed directly into the Duwamish.

In 1940, the City of Seattle built the first sewage treatment plant on the Duwamish. Treatment in those times addressed biological wastes, not chemical ones. Plus, the surge of development during WWII quickly outstripped the plant's capacity, so that much of the area's sewage flowed directly into the waterway. In 1959, the pollution of Lake Washington, where lakefront residents could not swim safely, catalyzed creation of a regional sewage utility, Metro. Over the next two decades, the City of Seattle partnered with Metro to separate stormwater from sewage in order to free up capacity in the sewer system. The separation projects meant Metro could build trunk lines to convey sewage to a new major treatment plant at West Point. Stormwater was considered relatively harmless, and therefore continued to flow into the Duwamish. Today, rain continues to fall and stormwater goes into the Duwamish.  Sewage does, too, when the pipes are overloaded.

When people ask who will pay to clean up the Duwamish, the answer is, "All of us." Many of the industries that dumped wastes into the waterway are long gone. Those that remain will share the cleanup costs, but so will current Seattle residents and businesses. We have all polluted the waterway. We pollute it every time we drive a car and flecks of metal come off the brake pads; every time we water a lawn and wash fertilizers and pesticides into the storm drain. We pollute less directly but with more of a chemical punch when we buy plastics and other products, such as cosmetics, which release phthalates. Pthalates have become ubiquitous in our urban environment and will continue flowing into the Duwamish as long as they are in the products we buy.

The City Attorney's Office has worked with staff at Seattle Public Utilities, Seattle City Light, and other departments for the past 16 years regarding the Duwamish. We have been there while scientists and managers wrestle with the best way to investigate contamination in the waterway and the options for addressing it. Now we are representing the City in a process to voluntarily resolve which entities will pay, and how much they will pay, for the cleanup. Forty-seven parties, including the City of Seattle, the Port of Seattle, King County and The Boeing Co., are participating in a kind of confidential mediation. They have agreed to share their information on pollution in the waterway and to pay for a neutral person, called the Allocator, to assign them shares of the cleanup costs. Since the cleanup strategy chosen by the U.S. Environmental Protection Agency, is currently estimated to cost $340 million, even a small share of liability can be painful. Parties do not have to accept the share assigned to them by the Allocator, but everyone knows that those who reject their assigned shares are likely to be sued by the others.
In order for the allocation process to succeed, the parties have to be thorough and transparent in disclosing how they may have polluted the waterway. This information is confidential because the process is a voluntary mediation.

Over the next few years, the allocation process will continue, while EPA works with a small group of parties, including the City, on further studies that are needed before cleanup can begin. Then dredging will start in some parts of the waterway. Other areas will be capped with clean material and others will be monitored over time to see if they are buried with clean sediment coming from upriver. The dredging and capping work will take seven to 10 years. Monitoring will continue for decades.

The Duwamish waterway will never again be a free-flowing, completely clean river. The best we can do with today's technology is to make it clean enough that it will not be a major threat to human health. Sadly, people will not be able to eat an unlimited amount of shell fish or bottom fish, because the sediments where those creatures live cannot be cleaned enough. Our society is paying for the economic boom times of the past and for our current dependence on products that release toxic chemicals into the environment. It will take a cultural shift and a great deal of time for the future of the Duwamish to be truly bright.