3718 Denmark Ct - Construction of Alum Settling Basin Letter4 City of Eapll.
Mike Maguire
Mayor
Paul Bakken
Cyndee Fields
Gary Hansen
Meg Tilley
Council Members
Thomas Hedges
City Administrator
Municipal Center
3830 Pilot Knob Road
Eagan, MN 55122 -1810
651.675.5000 phone
651.675.5012 fax
651.454.8535 TDD
Maintenance Facility
3501 Coachman Point
Eagan, MN 55122
651.675.5300 phone
651.675.5360 fax
651.454.8535 TDD
www.cityofeagan.com
The Lone Oak Tree
The symbol of
strength and growth
in our community.
October 4, 2010
Marty and Linda Haugen
3718 Denmark Ct E
Eagan MN 55123 -1007
Dear Mr. and Mrs. Haugen,
Thank you very much for your September 23, 2010 letter addressed to the Eagan City Council, the
citizens of Eagan, and me about the City's plans to construct an alum settling basin in your
neighborhood this fall. Your letter raised several questions and concerns about the overall alum
treatment system that will help satisfy water quality requirements for Fish Lake. On behalf of the City
Council, please accept the following responses to your questions and concerns.
1. "Will the alum settling basin be designed and constructed with the expectation that it will be
operated and maintained as an engineered structure for the indefinite future?"
The alum settling basin is designed and will be constructed for optimal operation and maintenance.
The basin size and volume, coupled with the stormwater pumping rate, will provide appropriate
treatment and settling times. The basin and site configuration will allow efficient sludge removal.
Beginning 2011, the City expects to operate the treatment system annually from April through
September for at least 10 years. To optimize system operation and maintenance, the City will be using
the lowest, most effective alum dosing rate over the shortest possible time period, depending on
evaluations of lake water quality monitoring data. Based on ongoing experience and monitoring,
dosing may occur regularly and/or intermittently. Eventually, the system may be run at a reduced level
or no longer if water quality improvements in Fish Lake result from significant reductions of
stormwater runoff implemented at a watershed scale in the next 10 -plus years.
The 2 -year study of Fish Lake approved by the U. S. Environmental Protection Agency September 9,
2010 assumes the water quality goal can be achieved exclusively by reducing phosphorus from
watershed runoff. To remove Fish Lake from Minnesota's impaired waters list sooner rather than
later, the treatment system has been selected as the most effective strategy. Although the City could
accomplish necessary phosphorus reductions solely by the treatment system, comprehensive lake and
watershed management is the City's 20 -year, enduring tradition. This means ongoing programs for
public education and outreach, priority street sweeping, aquatic plant management, stormwater system
maintenance, and monitoring will continue indefinitely.
"Is there an expectation that at some point the basin will be converted to a natural water body or
a waters of the state? And if so, what will the restoration /mitigation plan entail?"
No. Since the 1995 -2000 Fish Lake Clean Water Partnership Project, which was supported by a
Minnesota Pollution Control Agency (MPCA) grant, a main reason to construct an alum settling basin
has been the need for an "off- line" basin that is not a water of the state. This was a central issue when
the State granted the City the 5 -year limited permit in 1998 -2002 to operate the treatment system
temporarily using a water of the state (Pond JP -47). As you know, the City exercised the permit for
only three years (1998 -2000) and subsequently removed alum sludge from JP -47.
2. "How will solids that accumulate in the basin be removed and disposed of?"
For over a year, City staff, our consulting engineers, and MPCA staff have devoted a great deal of
thought and discussion to the settling basin. The final basin design allows us to evaluate costs and
benefits of two options and to select one of the following to remove sludge: 1) externally pump and
Mr. and Mrs. Haugen, October 4, 2010, page 2 of 4
haul overland and 2) internally pump into the sanitary sewer. For the first option, disposal would meet MPCA
requirements; for the second option, disposal to the Seneca Wastewater Treatment Plant would be according to
Metropolitan Council Environmental Services requirements.
"What is the expected frequency at which you expect solids to be removed?"
Initially, we expect to remove sludge from the basin once a year and optimally during a period of several days.
Based on ongoing experience and monitoring within the first few years, the City should have an operations and
maintenance strategy to guide appropriate dosing rates and timings that may result in different removal
frequencies and during different removal periods. This approach will not only help the City best meet the goals
for Fish Lake, but also minimize operating costs of the facility and reduce maintenance expenses of the basin.
"What actions are being taken to mitigate the vehicle traffic and potential nuisance odors associated with
both the general operation and the removal of solids from the basin?"
The City is acutely sensitive to the effects of its citywide activities on residents, and this operation is no
different. We think nuisance odors in JP-47 were from air exposure of sludge in 2000, when a significantly
increased dosing rate and unusually high volumes of stormwater from the "Super Storm" caused most of the
sludge to accumulate. The design of the 10 -ft deep settling basin allows sludge to accumulate underwater about
five feet deep before removal would be required. Nuisance odors may occur during maintenance activities,
depending on the removal options previously discussed. Similarly, vehicular traffic will vary between removal
options. These and other factors will weigh in the evaluation and selection process for long -term maintenance.
3. You provided the following comments: "The letter notes that the city operated the alum- dosing facility on
a trial basis between 1998 and 2000 and achieved very good results. As owner of the land adjacent to both
sides of Pond JP -47 we would like to officially go on record disputing that statement. Not only did the
alum dosing to the pond result in a complete kill of all of the natural wildlife, the subsequent odors and
nuisance conditions resulting from alum treatment took years to be restored."
The alum facility was built in 1998 with funding from MPCA's Clean Water Partnership program for the
specific purpose of reducing phosphorus entering Fish Lake. The letter to which you referred invited residents
to a public meeting September 23, 2010 about the settling basin plans. "Very good results" is our conclusion of
improvements in Fish Lake water quality in 1998 -2001, which are shown as significant phosphorus reductions
(encircled) in the figure below:
110
100
90
80
70
60
50
40
30
20
10
1991 -2009 Fish Lake Total Phosphorus
Summer (aurae - September) Average
0
1990 1992 1994 1996 1998
1991 1993 1995 1997 1
2000
9 2001 2003 2005 2007 2009
Year
2002 2004 2006 2008 2010
=tt Mean
• Mr. and Mrs. Haugen, October 4, 2010, page 3 of 4
The City regularly monitored the alum treatment system from Hurley Lake to Fish Lake during the 1998 -2000
operation. Not having found any evidence or received any reports by residents of dead animals in JP -47,
indicative of "a complete kill of all of the natural wildlife," we believe there were significant impacts primarily
to aquatic plants and small aquatic organisms in 2000, when sludge accumulated to nearly two feet deep, as
you undoubtedly recall. This significant amount of material settled within a relatively short period of time and
also probably displaced mobile animals such as herons, egrets, and ducks from JP -47. Again, we think odors
and nuisance conditions occurred from exposure to the air of this excessive amount of sludge in 2000. The
City is not planning to use a similar high dosing rate in the future.
With federal Clean Water grant funding, University of Minnesota researchers Pilgrim and Brezonik evaluated
the potential adverse effects of lake inflow treatment using data collected from Eagan's Fish Lake system and
Oakdale's Tanners Lake system. Their research, published in 2005 in the scientific journal Lake and Reservoir
Management, acknowledged alum accumulation in 2000 "smothered benthic macroinvertebrates and aquatic
macrophytes" in JP -47. They concluded potential adverse effects of inflow alum treatment can be averted by
using a properly designed system that will capture a significant fraction of the sludge in a settling basin. With
such a system, they concluded, there is little risk of aluminum toxicity, given expected pH levels in the water
and the range of dosing rates the City will be using. Pilgrim and Brezonik referred to the value of system
monitoring, which the MPCA will require the City to do.
4. You provided the following comments: "Furthermore we would like to note that the City has had a
complete lack of disregard for the neighbors directly impacted by the proposed project. Previously the
City indicated that the basin would be located in a different location (west of the trees in the lot in Mr.
McCarthey's property close to Hurley Lake) and without warning or conversation with those of us with
homes directly adjacent to JP -47, they have now changed their plan. Based on what we consider the poor
environmental results of the 1998 treatment, we think this represents woeful public participation and
outreach on the part of the city."
Fish Lake has been the subject of the most study and the most public involvement of any lake in Eagan's
history. After the City Council adopted Eagan's first water quality management plan in 1990, the Advisory
Parks, Recreation, and Natural Resources Commission (now Advisory Parks Commission) appointed a Fish
Lake Steering Committee (FLSC) in 1993. The FLSC comprised four residents who provided guidance in the
development of a feasibility study and implementation plan. The FLSC held two widely advertised public
meetings March 24, and July 13, 1994 that provided information and solicited input on possible
implementation elements, including an "alum injection system." My predecessor, Rich Brasch, met
specifically with JP -47 residents about the proposed alum injection system on July 16 and 30, 1994. You
probably recall Rich contacting you by phone. Numerous articles were published and briefings were made in
1994 -1995 to the Advisory Commission and the City Council on Fish Lake plans.
The subsequent 5 -year period (1995 -2000) corresponded to the Fish Lake Clean Water Partnership Project,
through which the alum system was constructed, operated, and monitored. A letter requesting comments and
questions was sent to neighborhood residents on June 15, 1995. During 1995 -1996, a pilot study of alum
dosing rates was conducted prior to 1998 construction of the building. Rich Brasch's letter to you and fellow
JP -47 neighbors on June 11, 1997 communicated the latest efforts of the project and requested comments on it.
This letter was followed up by a public input meeting on June 26, 1997. After the last year of operation (2000),
the City Council in 2001 began considering the short-term and long -term management of JP -47, and whether
to operate the dosing facility again. It held a workshop January 17, 2002 to discuss relevant issues with City
staff. Undoubtedly, you recall the subsequent series of public information meetings and Council meetings (at
least one of which you attended) that focused on this topic in 2003 (January 15, February 4, March 25, October
1, December 8, and December 16) and in 2004 (January 27, February 10, and March 9), and you remember the
Council's directive for staff to report about alum alternatives and proposed future costs and timelines. The
Public Works Committee reviewed this report in early 2004 and specifically directed me to follow through
with you for an update on the project. As you know, since sludge removal from JP -47 in early 2004, there had
been no public outreach specifically about the alum project until relatively recently, after complicated legal
issues about Mr. McCarthy's property were resolved. During the 2 -year study of Fish and Schwanz lakes, the
Mr. and Mrs. Haugen, October 4, 2010, page 4 of 4
City sponsored publicized open meetings on June 18, 2008, January 29, 2009, and February 10, 2010, during
which the Fish Lake alum treatment system was discussed among other possible management options.
Continuing with this past practice, the September 23, 2010 meeting is another example, although the first
public meeting specifically about the alum treatment system and JP -47 in over six years, of the City's desire to
keep the public informed and involved in this important endeavor.
Regarding basin location, the 1994 Fish Lake diagnostic /feasibility study discussion of an "alum injection
system" includes a graphic of the preferred basin located directly east of JP -47 on Mr. McCarthy's property.
There has never been any other preferred location for this basin. The primary concern in 1994 was having
insufficient treatment volume in JP -47. Locating the basin "close to Hurley Lake" has never made financial or
practical sense because it would require a separate lift station and there would be an insufficient length of pipe
for alum to mix with stormwater before discharge to the basin.
In 1994, it was widely accepted practice to use wetlands (such as JP -47) for stormwater treatment. Thus,
because of private property concerns with the preferred McCarthy site, the selected alternative of the 1994
diagnostic /feasibility study was to use JP -47 for primary settling and to excavate the wetland to an average
depth of at least 4 feet. To address existing conditions after the 2000 operation, the Council approved plans in
2002 to remove sludge and excavate only a small sedimentation basin at the east end of JP -47. These plans
required the City to replace wetland impacts according to Wetland Conservation Act (WCA) rules. After
receiving bids in early 2003, however, the City's consultant indicated there would be technical difficulties
meeting State water quality standards for dissolved aluminum in JP -47. This essentially eliminated the City's
ability to operate the alum treatment system until a settling basin was constructed outside of JP -47, as preferred
in 1994. The Council rejected the original 2002 project and awarded a contract only to remove sludge,
consistent with WCA rules. During this time, the Council also directed the beginning of a process to acquire
property east of JP -47.
Thank you again for your interest in the City's efforts to enhance the quality of Fish Lake as represented in
your letter, as well as your attendance at the neighborhood meeting on September 23. I hope these responses
address your questions and concerns.
Eric Macbeth
Water Resources Coordinator
Attachments: 1. September 9, 2010 City of Eagan letter
2. September 23, 2010 Mr. and Mrs. Haugen letter
Cc: Mayor and City Council c/o Tom Hedges, City Administrator
Tom Colbert, Public Works Director
Russ Matthys, City Engineer
q uiet
b reeze music /many haugen
(612)810- 1791 -phone • martyhaugen@mac.com - e -mail
3718 denmark court east • eagan, mn 55123 -1007
September 23, 2010
To the Mayor and members of the Eagan City Council (Mike Maguire, Paul Bakken, Gary Hansen,
Cyndee Fields, Meg Tilley), Eric MacBeth, Water Resources Coordinator to the City of Eagan, and the
citizens of Eagan:
I am offering this letter on behalf of myself and my wife, Linda. In our questions and concerns about
this project, we have asked for and received help from our daughter, Katrina Kessler, a water quality
engineer at the Minnesota Pollution Control Agency. Here are some questions we would like to raise:
Will the alum settling basin be designed and constructed with the expectation that it will be operated
and maintained as an engineered structure for the indefinite future? As a follow up, is there an
expectation that at some point the basin will be converted to a natural water body or a waters of
the state? And if so, what will the restoration/mitigation plan entail?
How will solids that accumulate in the basin be removed and disposed of? What is the expected
frequency at which you expect solids to be removed? What actions are being taken to mitigate
the vehicle traffic and potential nuisance odors associated with both the general operation and
removal of solids from the basin?
The letter notes that the city operated an alum - dosing facility on a trial basis between 1998 and 2000
and achieved very good results. As owner of the land adjacent to both sides of Pond JP -47 we
would like to officially go on record disputing that statement. Not only did the alum dosing to
the pond result in a complete kill of all of the natural wildlife, the subsequent odors and
nuisance conditions resulting from the alum treatment took years to be restored.
Furthermore we would like to note that the City has had a complete lack of disregard for the
neighbors directly impacted by the proposed project. Previously the City indicated that the
basin would be located in a different location (west of the trees in the lot in Mr. McCarthey's
property and close to Hurley Lake) and without warning or conversation with those of us with
homes directly adjacent to JP -47, they have now changed their plan. Based on what we
consider the poor environmental results of the 1998 treatment, we think this represents woeful
public participation and outreach on the part of the city.
On this day of significant rainfall in Eagan, we also would ask that, if you construct a sediment basin
and, as will certainly eventually happen with another heavy rainfall, will the city have to release the
alum into the water stream?
Fish Lake Alum- Settling Basin, September 9, 2010, Page 2
Despite exemplary efforts by the Eagan's comprehensive water resources program since 1990,
the MPCA listed Fish Lake as impaired in 2006 for aquatic recreation due to excessive nutrients
(i.e., phosphorus). In cities throughout Minnesota,
high phosphorus levels come from lawn
clippings, fertilizer, and street debris in natural filtration by the ground. Too much phosphorus
sewers and directly into lakes without n
often leads to excessive plant and algae growth.
Based on historical results, the City plans to re- establish ana is expected treatment d to be similar d o e
phosphorus from Fish Lake. The system's future performance
effectiveness. Within 10 years, there should be adequate basis for MPCA to remove
Fish Lake from the state impaired waters list.
Thank you in advance for your interest. I look forward to seeing you on the 231-d! Plase questions feel free
have any
contact me at (651) 675 -5300 or emacbeth ! cit ofeatan.com if you y
issues you would like to discuss.
Sincerely,
Eric Macbeth
Water Resources Coordinator
Cc: Mayor and City Council c/o Tom Hedges, City Administrator
Tom Colbert, Public Works Director
Russ Matthys, City Engineer
Barb Peichel, MPCA
Chad Davison, Bonestroo