Waughop Lake – the rest of the story
Submitted by
Paul A. Bucich, P.E., Public Works Engineering Director, City of Lakewood.
Recent
articles published in the Suburban Times regarding Waughop Lake have not
included all the facts around how the City arrived at its decision to apply
alum treatments to the lake to control toxic algae blooms.
There
are many opinions on what to do about the lake, from do nothing to dredge it
and start over. We believe we have found a solution through a management
strategy that addresses the issue in a reasonable manner that is affordable and
has the smallest impact on Fort Steilacoom Park, park users, and surrounding
neighborhoods.
As
most users of Fort Steilacoom Park know, toxic algae in Waughop Lake is a
decades-long problem. In its search for a solution, the City consulted with
national experts and state ecology officials, held extensive discussions with
University of Washington professors and others with expertise in lakes and
aquatics issues, and listened to residents.
In
an effort to make sure the City had all the information before proceeding with
a treatment option, two independent consultant firms were hired to provide
recommended treatment options.
The
suggested solutions proposed by Mr. McClellan (Jan. 14 “Lakewood is on the wrong path for its biggest environmental
problem“) and Mr. Russell (Jan. 11 “Letter: Council should reconsider Waughop Lake plan“)
fail to mention key information that led the City Council to its final
decision.
That
information is outlined below:
Lake
Dredging
Nationally
recognized consultants have evaluated options for addressing the algae blooms
in Waughop Lake, including treatment with Aluminum Sulfate (alum) or hydraulic
dredging of the bottom sediments. Consultants hired by the City, Brown and
Caldwell as well as Tetra Tech, independently assessed the feasibility of
treatment options and the costs of alum treatment vs. dredging. The 2017 Brown and Caldwell report recommended
the following management strategy: “Conduct further lake sediment
assessments to provide more accurate costs for sediment removal; if costs are
higher than City can fund, conduct whole-lake alum treatment to remove
phosphorus from the water column and inactivate phosphorus in the sediment;
evaluate if sediment removal long term is feasible in regards to permitting
requirements, costs for operations, impacts to park users.”
This
is the strategy the City has followed since 2017. In 2018 the City hired Tetra Tech to conduct another review, this time
asking specifically about dredging costs. Work done in 2018 and already in 2019
revealed the high cost of sediment removal and the impacts it would have on the
park and adjacent neighborhoods.
Removal
of sediments from a lake bottom is challenging even when a suitable location
for disposal of that sediment is adjacent to a lake. In the case of Waughop
Lake, it is even more challenging because the City is not able to dispose of
the sediment within Fort Steilacoom Park without having a significant impact on
existing park uses and features.
The
2018 study by Tetra Tech determined that the costs to dredge the lake ranged
between $7.9 Million and $34.5 Million depending on the depth of materials
removed. With a shallow removal, the probability of success was estimated at 20
percent. With a deeper dredging effort, the probability of success was
estimated at 90 percent. Success is viewed as significant reduction or
elimination of algae blooms.
The
significant impact of dredging was not relayed in the recent articles in the
Suburban Times. It is important for the public to understand all the impacts
the City Council considered when making its decision.
Dredging
requires a significant operation including pumping the materials, drying the
materials, and transporting them off-site.
It
was estimated a 20-acre “pond” would be needed as a drying facility to dry the
materials. This facility would be six feet deep and would be built on top of
the existing ground so as to not disturb any potential artifacts in the park.
The
facility would be lined with an impermeable layer to ensure stability to hold
the liquid/solids. As the dredged material dried, we would expect an odor to
develop (think of the beach at low tide but worse) that would affect park
users, nearby neighborhoods, Western State Hospital, and the commuting public.
Hydraulic dredging of the material with the expected branches, rocks, and other
debris would be challenging. Further, we anticipate the dredging/drying/removal
process would require significant closures of large areas of the park for up to
two years. The lakeside trail would be closed to public access during the
dredging operation which would most likely occur during the summer season(s).
Disposal is
Problematic
It
was suggested that this material is equivalent to Tacoma’s Tagro product based
on an analysis of the nutrient loadings alone and that it has a market value.
What is missing from this assertion is the complex nature of the bottom
sediments. We fully expect to find organic materials such as logs, branches,
bones from fish, waterfowl, and potentially detris from the historic use of the
lake by Western State Hospital such as bones, bottles, bricks, etc. These
materials would need to be separated in the removal process, some by the
hydraulic pumping system installed to move the loose bottom sediments, the rest
by any product manufacturer prior to sale. It is unclear if the dry material
can be used freely or if there is additional processing that would be needed.
Tagro
is a product that the City of Tacoma has spent over 30 years perfecting and is
a blend of bio-solids and other weed free garden products composted to rigorous
standards prior to sale. It is unrealistic to expect any topsoil manufacturer
to take on the lake sediments at no or minimal cost without additional
processing. The market for this product is unclear and as such, we have to
anticipate disposal at a landfill.
‘Alum is
Toxic and Short Lived’
Statements
have been made that alum treatment is dangerous, environmentally toxic to the
lake, will lead to an explosion of aquatic weed growth, is limited in life
span, will not work in a shallow lake, and not a preferred option by experts.
These statements are misleading and in some cases outright wrong.
Alum
treatment is a nationally recognized treatment process and deemed safe by state
and federal agencies after extensive testing and review. Alum is a nontoxic
material commonly used in water treatment plants to clarify drinking water. In
lakes, alum is used to reduce the amount of the nutrient phosphorus in the
water. Yes, there have been instances where applications in lake environments
have failed. These are almost exclusively due to applicator error. To address
this, the City will contract with our design firm to ensure a qualified expert
is on hand to oversee the application to Waughop Lake. The expert we are
working with from the consulting firm of Tetra Tech has over 40-years’
experience, is a nationally recognized Ph.D water quality scientist and expert
who has designed and overseen the treatment of over 200 lakes.
Failed
alum treatments are usually due to a lack of understanding of the sources of
nutrients leading to the algae blooms. Waughop Lake has no external sources
other than runoff from the park and the adjacent college and we expect a
successful application. We are currently evaluating the sediment concentrations
and refining the treatment needs of the lake to more accurately plan the alum
concentrations needed for the treatment.
The
City understands that alum treatment is not a one-time event. The typical
treatment life span is between 5-10 years at which time a smaller treatment is
likely going to be needed. This known aspect of alum treatment, when compared
to the costs and impacts associated with dredging the lake, is deemed
acceptable. Alum has not been determined to be environmentally harmful to any
of the number of lakes treated over the past decades of use.
But What
About…
It
has been suggested that the City treat the lake with algaecides and herbicides
in lieu of an alum treatment; that this is a viable management approach for the
lake.
When
we hired Tetra Tech, the City specifically asked for this option to be
reviewed. The expert we are working with said:
“Given
the level of ‘production’ within Waughop Lake, algaecides are not a sustainable
approach for reducing and controlling” the algae blooms. The City was told
repeated use will affect the food chain abundance leading to reduced water
quality and affect the fisheries food base. It will also likely lead to
groundwater and sediment contamination — the issue being presented by some as
the reason not to use alum. Algaecide would have to be applied repeatedly
throughout the summer, likely every 14 to 21 days, due to the reproduction
cycle of algae. Aquatic herbicides would only be used if the clarity of the
water reaches the point where aquatic plant growth impacts lake uses; this
strategy would be applied even with the alum treatment strategy.
The
City was approached by Mr. Russell who asked we try a new process being used on
a lake in Federal Way. We informed him that in our opinion, this was an
experimental process with an uncertain potential for success. We declined and
explained that we were not set up to do the required testing for an
experimental process. We encouraged him to contact larger agencies dealing with
similar issues on lakes to see if they would be willing to have their lakes be
the testing grounds for this treatment. Should it be successful and develop a
proven track record, we would consider this new treatment process on future
applications. At this time, we are unaware of any agencies taking on this new
treatment alternative.
Funding for
Treatment
Treatment
with alum has been estimated to cost between $300,000 and $750,000. Current
tests of Waughop Lake will provide a more refined plan for treatment and a
better cost estimate. The City has applied for a $50,000 grant from the
Department of Ecology to assist in treatment of Waughop Lake and received
confirmation from Pierce County that a $300,000 Flood Control Zone District
allocation for Lakewood can be used for this application. In our application
for the Ecology grant, we were clear the money was to be used for alum
treatment. Additional funding, if needed, would come from the City’s Storm and
Surfacewater Utility fund.
The State
Should Do It
In
1967 the State of Washington transferred the operational responsibilities for
Fort Steilacoom Park to Pierce County through a lease. That lease was
subsequently transferred to the City of Lakewood. The agreement releases the
State of Washington from any and all responsibilities for virtually anything
related to the park lands. There are improvements the City plans on making to
the park and we have been very successful obtaining state grants for past and
current improvements. There are no established grants we could apply for to
dredge the lake, and if there were, the impacts to the park and surrounding
properties would still remain.
The Answer
is Clear
Removal
of the bottom sediments through hydraulic dredging or other means is difficult,
expensive, and fraught with significant unknowns. Impacts to the park users and
adjacent neighborhoods are likely to be high. Impacts to the park will be
extensive. When compared with the alternative of alum treatment, a well-known
and permissible process, the choice is clear, alum treatment is the viable
solution at this time.
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