Seattle Press on Line - The Health of Lake Union

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The Health of Lake Union

By Stevan Morgain

A Foss tug gets a propeller re-fit at Lake Union Drydock.

Apr 21, 1999 -- Lake Union? It's still there. Harder to see behind the many new apartment and office buildings filling in the cityscape, but still there.

The lake's rhythms appear the same: a place where shipbuilders and seafood processors mix it up with marinas, houseboats, offices, restaurants and floating homes.

And despite Seattle's growth, the watery jewel is alive and doing well, according to Dr. Robert Chandler, environmental specialist with Seattle Public Utilities.

"It's been a long process, but we managed to improve the Lake's diversity and water quality improves yearly," Chandler says.

This has not always been the case. Early this century the 560-acre lake supported heavy industry. At the south end, ship yards overhauled everything from military transports to John Wayne's yacht. Westlake Avenue was once a cow path built from the sawdust of the lumber mills that crowded the lake's shoreline, while on the east side fish packers crammed salmon into cans and house boaters pumped raw sewage into the water.

"It was a real cesspool," said Chandler. "At the turn of the century even the city pumped raw sewage into the lake. It was so bad that in the late 1890s the city had an outbreak of typhus that was traced to the lake."

Chandler said that it was this legacy of disease that lead to the formation of three new city departments: the Seattle Engineering Department, Seattle Public Utilities and the Seattle Department of Ecology.

Further mucking Lake Union's water quality was the water flowing in from Lake Washington. In the 1950s there was a population boom in the communities lining the shores of Lake Washington. Construction growth, new roads and sewer development added more pollutants to both lakes. Millions of gallons of road contaminants and yard pesticide runoff were dumped into the lake basins.

In 1950 the lakes became so polluted that dozens of lakeshore communities formed the regional consortium known as Metro in order to construct a sewer system to divert waste water to what are now the primary waste treatment plants in Magnolia and Renton.

But that wasn't enough. A 1984 study by the National Oceanographic and Atmospheric Administration (NOAA) found that, after 100 years of heavy use, Lake Union was a toxic soup of heavy metals. High levels of mercury, zinc and copper floated at various depths in the Lake as well as being buried in the lake bed.

Pollutants continued to pour in from sewer overflows. Street and highway runoff contributed during peak wet seasons.

The 1984 study also said boating activities in and around Lake Union chipped in their share of pollution, dumping oil, paints and lead into the lake. Pollutants continued to leach from the soil in and around the original Gas and Coal Plant (now Gas Works Park). Small amounts of pesticides and fertilizers were also percolating into the water from yards close to the shore line.

Lake Union pollution forced Metro to comply with the Federal Clean Water Act. In doing so the city implemented the Combined Sewer Overflow (CSO) project, which has allowed it to build a sewage treatment system capable of handling waste that would otherwise be dumped "raw" into Lake Union during the winter flood months.

The CSO project is a multi-level filtration system that takes high levels of contaminated waste and separates it into reusable water and biosolids, which are then re-sold as fertilizer and compost.

"The CSO project is still under way but it's already beginning to have an impact," said Dr. Chandler. "The idea is to reduce the number of yearly overflow events and treat both sewer and storm water at the same time. The good news is that most of the time it works. Its only when we get abnormal rain fall that the sewers overflow and dump raw sewage into the lake."

SPU says that despite problems in localized areas, the Lake's surface water is in good shape.

A1994 study by SPU said that the 20 years of work to correct past pollution problems have been effective. The overall pollutant loads have measurably improved. The detection of heavy metals is infrequent and in concentrations well below normal water quality standards.

However, the study said some sediment locations around the lake, most noticeably Gas Works Park, still exhibit elevated contaminant levels of toxic metals, organic chemicals, and polycyclic hydrocarbons.

Another problem is dowtown growth. Downtown and nearby Lake Union are the fastest-growing neighborhoods in Seattle. Population density for this area grew from 17,597 in 1990 to almost 22,000 in 1996, according to estimates prepared by the Puget Sound Regional Council in 1997.

Another factor in Lake Union's pollution problems is the water environment created by the Hiram Chittenden Locks and the Cedar River dam. Lake Union receives all of its water from Lake Washington, which gets most of its water from the Cedar River. Through the years the river's water flow has been restricted to 120 cubic feet per second, far below original rates.

"This really isn't enough to thoroughly flush the lake," said Carol Anderson, director of Friends of Lake Union. "Our watchdog group has seen a noticeable increase in temperature."

Studies show Lake Union's water flow has warmed to a yearly average of 70 degrees in parts of the lake and ship canal. Biologists say that the ideal temperature for salmon to pass through the canal is about 60 degrees. "Therefore there is a thermal barrier preventing many Chinook and Sockeye salmon from migrating beyond the cool, brackish water that swirls near the Ballard Locks," said Anderson.

Anderson said that the warmer weather also depletes oxygen levels in the ship canal, putting a virtual chokehold on salmon moving into Lake Washington.

Several recent studies say the best way to monitor Lake Union's water quality is by also measuring the riparian zones along the lake and animal life in and around the lake.

"I like that idea," said Anderson. "Lake Union has the biggest bass population in the state. My husband and I regularly fish the south shore. It would be nice to know the fishes' quality of life was being monitored, too."

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Dave Galvin	Mar 25, 2004	Seattle	environmental manager, King Co
A date of publication for articles such as this one, "The Health of Lake Union," would be helpful on your website. I found it via a Google search, but I can't seem to find a date of when it was published. Thanks. -- DVG