By Tom McClellan.
The Lakewood City Council needs to change course on the plan to dump chemicals into Waughop Lake.
We need to go back to the course of action that every study has recommended for remediation of the toxic algae problem, which is to remove the phosphorous-laden sediments which are fueling the excessive algae growth.
Why Is This A Problem
From the 1880s until 1965, Western State Hospital used the land which is now Fort Steilacoom Park to operate a farm. The farm served two purposes: it provided meat, fruit, and vegetables to the patients and staff at the hospital, and it also functioned as an occupational therapy outlet for the patients.
The change came in 1963, when the federal government decided that if institutions like Western State Hospital were going to employ patient labor, then they had to be paid the “prevailing wage” for such work. That change made the farm uneconomical to operate, and it was shut down in 1965. Eventually the land was transferred to Pierce County to serve as a park, and also to build Pierce College. The City of Lakewood later took over management of the park from Pierce County.
During the time that the farm was operating, Waughop Lake was not viewed as a precious natural resource in the way that we would view it today. Its water was used for irrigating crops, and it was also used as a dumping ground for both human sewage and farm waste. A slaughterhouse was built on brick pilings right over the lake, which made for easy disposal of the offal. A pig sty was built right next to the lake in the southern corner (where a new dock has been built), which made cleaning out the pig sty much easier. The workers could just shovel the pig manure right into the lake; problem solved! And the famous Hill Ward building (which is now just a monument) had a sewer pipe which ran straight down to the lake from the building’s toilets. Problem solved!!
The farm’s managers did not see this as a problem. A 1930 Scientific American article noted that the lake bottom sediments had proven to be such a rich source of nutrients that were used as fertilizer for both the patients’ garden plots and for the field crops. So adding back the farm waste and human sewage was seen as a way to restore an important farm resource.
Because Waughop Lake is a “kettle lake” with no real outflow, everything that gets dumped in the lake stays there. So all of the phosphorous in the human and animal sewage stays in the lake, and helps to fuel the persistent toxic algae blooms which make the lake unusable for swimming or other human contact. Algae cells need phosphorous to grow just like land plants do, and so when there is a lot of it in the lake, then we see a lot more algae growth, plus a lot of aquatic plants as well.
In addition to the farm operations, Waughop Lake also received periodic discharges of human sewage from Pierce College over a period of several decades. More than 40 years ago when Pierce College was first built, the design of its sewage system involved draining the waste to a “lifting station” at the bottom of the hill, located between the college buildings and Waughop Lake, from which it was pumped back uphill to the sewer lines on the west side of the college. But the plumbers who installed that system added a cross connection so that if the lifting station pump ever failed or got overwhelmed by volume, then the excess was diverted into a stormwater pipe running into Waughop Lake.
That plumbing project has now been fixed (you may have seen the work being done over the past 3 months), but the 40 years’ worth of occasional human sewage discharges are still present in the lake. And those “nutrients” are adding to the excessive algae and aquatic plant growth problem.
How potent are those “nutrients”? According to sediment coring data gathered by the University of Puget Sound, the top meter of sediments has nitrogen, phosphorous, and potassium (N-P-K) levels roughly equivalent to TAGRO fertilizer, which is sold by the City of Tacoma’s sewer utility as a soil amendment.
The presence of all of these rich nutrients has resulted in Waughop Lake being in a “hyper-eutrophic” state. That is a fancy word which means that algae and plant growth are in such abundance that the dead plants and algae are piling up on the bottom of the lake.
While eutrophication of a lake is a natural process, coring data from the University of Puget Sound shows that it is happening in Waughop lake at a rate over 100x faster than in nearby Lake Louise, which does not have tons of farm waste dumped into it. In addition to the problem of the algae releasing toxins which are harmful to humans and animals, the eutrophication process means that Waughop Lake will become “Waughop Meadow” in just a few decades at the current rate of accumulation of sediments.
The Experts’ Recommendations
In 1978, the consulting firm Entranco Engineers of Bellevue, WA was engaged by Pierce County Parks and Recreation to study Waughop Lake and come up with a plan for restoration. They produced a 47-page study recommending that the phosphorous-laden bottom sediments be dredged and hauled away. Pierce County never acted on that recommendation.
In 2008, State funding was secured for an effort to apply calcium hydroxide to Waughop Lake, a treatment which is chemically similar to the application of aluminum hydroxide, or alum. The finding was that it was ineffective at isolating the plentiful phosphorous in the waterbody, and the algae persisted.
In 2012, with the City of Lakewood by then having taken over management of the park, a group of citizen volunteers and academic experts presented a 72-page study to the City, recommending that the phosphorous laden lake bottom sediments be removed through a combination of hydraulic dredging and mechanical removal. This study was prepared at no cost to the City, and employed data gathered by the University of Puget Sound and the University of Washington, Tacoma. It looked at all of the options for remediation of the toxic algae problems, finding that other methods would not achieve resolution of the problem.
The City of Lakewood accepted that study, but did not act on it because the City had already initiated a plan for a $250,000 study to be done by the consulting firm Brown & Caldwell.
In 2014 and 2015, Brown & Caldwell’s data gathering effort got underway. A finalized plan was presented to the Lakewood City Council on March 6, 2017. The consultants once again recommended that the lake bottom sediments be removed, in order to take the phosphorous out of the lake. But then they said that if the City wanted to do so, an aluminum sulfate (alum) treatment could be applied which would offer temporary benefit by having the aluminum ions bind to the dissolved phosphorous in the water, making them unavailable to the algae.
Rather than take in any other input about this recommendation, the City Council voted 6-1 to go ahead with pursuing an alum treatment. At that Council meeting, members of the public were allowed to speak on this topic at the beginning of the meeting, limited to 3 minutes per person, but no one was allowed to offer any information to rebut the consultants’ recommendation about pursuing an alum treatment.
How An Alum Treatment Works
When a lake is treated with aluminum sulfate (alum), trucks bring thousands of gallons of chemicals to the site, where they are loaded on a special barge which sprays it into the water.
Here is a picture of a lake being treated.
In the water, the aluminum sulfate molecules break apart into aluminum ions and sulfate (SO4). The chemicals also tear apart some of the lake’s water molecules (H2O), turning them into a hydroxyl (OH-) ion and a free hydrogen (H+) ion. The aluminum ions then bond with the hydroxyl to create a “floc” which quite bonds readily to the phosphorous compounds in the water as well as to other suspended particles, settling to the bottom of the lake and making the lake really clear.
The sulfate molecules are a bit of a problem, though, because once they are freed from the aluminum ions, they bond readily with hydrogen (H+) ions to make sulfuric acid. For that reason, a buffering agent has to be applied at the same time in order to prevent the lake from becoming too acidic and killing the fish, which is what happened when Wapato Lake was treated with alum in 2008. See www.thenewstribune.com/news/local/article141350118.html.
The alum-bound phosphorous then sits in a nice neat layer at the bottom of the lake, theoretically unavailable for plants and algae to use as a nutrient. And that works fine, for a while at least, as long as there are no other sources of phosphorous to be introduced into a lake via stream flow.
Alum treatments carry several risks, even when done in a lake where they are more appropriate. If the pH of the lake water is not within a fairly narrow band, then the chemistry magic described above can go awry, and the lake ends up with toxic aluminum compounds. And if the applicator does not mix and apply the chemicals properly, then it can kill all of the fish and other organisms, as Tacoma found out with Wapato Lake in 2008.
An alum treatment is supposed to last for 10 years. But Tacoma had to go back to Wapato Lake and do another treatment shy of that 10 year point. Green Lake in Seattle has had similar problems of alum treatments failing and the lake becoming eutrophic again well short of the advertised duration.
Why Alum Would be Bad for Waughop Lake
Waughop Lake is only 2 to 4 meters deep at its deepest point, depending on how much rain has fallen recently. In shallow lakes like Waughop, alum treatments lose effectiveness very quickly.
We know this from a University of Washington study, “Internal Phosphorus Loading and Alum Effectiveness in Shallow Lakes” which you can read here. The authors evaluated the effectiveness of alum treatments on several lakes in western Washington, finding that alum is less effective at locking up phosphorous in shallow lakes versus deeper ones. What happens is that the aquatic plants in a lake can dip their roots down into the sediments, below that nice neat layer of alum-bound phosphorous, and pull up unbound phosphorous to use for building leaves and stalks. The plants do this even more effectively after an alum treatment, because the water temporarily becomes nice and clear which fosters more sunlight absorption. Then as those plants eventually die and decay, the phosphorous that they pulled up from the deeper sediments once again becomes dissolved in the water.
In a deep lake, an alum treatment can work better because the alum carries the phosphorous all the way down to a deeper level where plants cannot grow because sunlight will not penetrate that far. But in a shallow lake, the sun can reach all the way to the bottom, stimulating plant growth, and making the treatment lose effectiveness much sooner.
Alum treatments are also ineffective in lakes like Waughop which have carp in them. And Waughop has a whole lot of carp, including some really big ones.
Carp are known as “benthivores”, meaning that they feed in the “benthic” region of the water column, which is the interface between the water and the bottom sediments. And as they do that, they stir up those bottom sediments while digging for food, thereby disrupting that nice neat layer of alum-bound phosphorous, and reintroducing the sediments from below that layer into solution.
The problem of carp and water quality was addressed in a 2001 paper, Catastrophic Response of Lakes to Benthivorous Fish Introduction, at www.jstor.org/stable/3547579?seq=1#page_scan_tab_contents
The expensive consultants which the City of Lakewood hired to develop the cleanup plan should have told the City about these two factors, shallow depth and the presence of carp, which will limit the effectiveness of any alum treatment. But they did not, and now the City is proceeding in this misguided plan which has significant environmental risks and is bound to fail a lot sooner than our City officials have been led to believe.
What needs to happen now is for the City Council to vote to change course, and abandon the alum treatment plan.
Here Is Where You Can Help
If you are concerned about the City proceeding on a misguided plan to add a bunch of chemicals to Waughop Lake, then please write to all of the City Council members. Encourage them to abandon this costly alum treatment plan, and pursue removing those phosphorous-laden bottom sediments.
Remind them that the State of Washington needs to be made to pay for that operation, since it was the State’s farming operation and the State-owned Pierce College’s sewer problem which created this situation.
Write to them at these email addresses, or c/o Lakewood City Hall, 6000 Main St SW, Lakewood, WA 98499.
Don Anderson email@example.com
Jason Whalen firstname.lastname@example.org
Mary Moss email@example.com
Michael Brandstetter firstname.lastname@example.org
Marie Barth email@example.com
Paul Bocchi firstname.lastname@example.org
John Simpson email@example.com
About the author: Tom McClellan lives in Lakewood, and has been a volunteer water quality monitor for the Pierce Conservation District’s Stream Team since 2000, including doing monthly monitoring on Waughop Lake. He oversees aquatic weed treatments on Lake Louise. He previously authored a 2-part series about Waughop Lake and the need to remedy the toxic condition, which can be read at these links:Print This Post