HomeMy WebLinkAboutagenda.council.worksession.20250203AGENDA
CITY COUNCIL WORK SESSION
February 3, 2025
4:00 PM, City Council Chambers
427 Rio Grande Place, Aspen
I.Work Session
I.A Board and Commission Interviews
I.B Water Treatment and Potable Water Quality Discussion
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Topic: City of Aspen Work Session
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Board & Commission Interviews MEMO - 2.4.25.pdf
Council Memo_WaterQualityWorkSession_FINAL.docx
Exhibit A - Aspen WTF Site Layout.jpg
Exhibit B - COA WTP Schematic_Feb 3rd Work Session.pdf
Exhibit C - coa.election.certificate.19890502.pdf
Exhibit D - memo and resolution.council.012-12-Flouride.pdf
Exhibit E - CWF Statement 2024-10-14.pdf
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MEMORANDUM
TO:Mayor and City Council
FROM:Ryan Loebach, Utilities Process Manager
THROUGH:Tyler Christoff, Public Works Director
Justin Forman, Utilities Director
CJ Oliver, Environmental Health and Sustainability Director
MEMO DATE:January 27
th, 2025
MEETING DATE:February 3rd, 2025
RE:Water Treatment and Potable Water Quality Discussion
_____________________________________________________________________
REQUEST OF COUNCIL:Staff have been invited to this work session to update and
discuss with City Council the state of water treatment and potable water quality provided
to the City’s water customers.
SUMMARY AND BACKGROUND:The City provides potable water to over 4,100
accounts within the water service area, producing between 1.1 to 1.7 billion gallons
annually. Raw water from Castle Creek or Maroon Creek is conveyed to the City’s
Castle Creek Water Treatment Facility, see attached Exhibit A, where the water is
treated in accordance with Colorado Primary Drinking Water Regulations.Safe potable
water is produced through a series of chemical and physical processes that remove
suspended solids and disinfect microbes. A schematic of the water treatment process is
attached as Exhibit B. Five treatment chemicals certified for water treatment use by the
National Science Foundation (NSF-60 certification) are added through the treatment
process:
Primary Coagulant: Aluminum chlorohydrate (ACH) is a water soluble liquid feed
into the raw water at the beginning of the treatment process. ACH dissociates
into an aluminum salt binding to suspended solids to create a settleable and
filterable particle.
Flocculant Aid Polymer: Polydiallyldimethylammonium chloride (polyDADMAC) is
a cationic polymer added after coagulant addition that provides additional ballast
to the particle formed by the primary coagulant to increase particle settling
efficacy. This polymer is used seasonally during runoff when suspended solid
concentrations are at their highest.
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Filter Aid: Sodium metasilicate is granular compound that when added to the
water after settling works with the primary coagulant to create a more filterable
particles creating increased filter run times.
Fluoride: Sodium silica fluoride is a solid fluoridation source that is batched into a
dilute solution and added to filtered water as part of the City’s community water
fluoridation program. This fluoride solution is added to water that has an average
natural fluoride concentration in the source water of 0.2 mg/L.
Bleach: Sodium hypochlorite is added to filtered water to disinfect the water
through contact time in the clearwell and provide a residual within the distribution
system to discourage the re-growth of microbes.
The primary coagulant, flocculant aid polymer, filter aid, and aqueous suspended solids
are removed from the aqueous phase and stored in the settling basins as settled solids
until they are removed from the basin to the residuals drying bed. Aqueous solids that are
not removed during sedimentation process, are removed through filtration (composed of
anthracite and sand). Fluoride and bleach are dosed prior to entering the clearwell and
remain in the water for the benefit of public health.
City staff follow Colorado Department of Public Health and Environment (CDPHE) oral
health unit and Safe Drinking Water Program recommendations in the administration of
the community water fluoridation program. This program ensures the addition of sodium
silica fluoride is in accordance with the latest scientific dental and health guidelines of
maintaining optimally fluoridated water of 0.7 mg/L. City staff are annually recognized by
CDPHE through the Water Fluoridation Quality Award for achieving a potable water
fluoride concentration between 0.6 mg/L and 0.9 mg/L for 75% of the year.
The City’s community water fluoridation program began prior to the 1980’s and has
continued to this day. Since that time, the public and council have approved the
continuation of the program via the following actions:
A 1989 City of Aspen ballot measure requested to continue community water
fluoridation. The public passed the measure, 1405 to 450 in favor of continuing
water fluoridation in the City of Aspen. See Exhibit C for the 1989 Election
Certificate.
Council passed Resolution 012 of 2012, see attached Exhibit D, to continue
community water fluoridation and adopt the fluoridation concentration we use
today in accordance with recommendations of the EPA and US Department of
Health and Human Services at the time.
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DISCUSSION:Public comment at recent council meetings and recent email
correspondence to council have expressed the public’s concern and/or support for a
community water fluoridation program. In addition, community water fluoridation has
been a topic of conversation through national media sources based on a Federal Court
ruling on recent fluoride toxicology studies in August 2024 and statements from the
newly appointed US Department of Health and Human Services director that indicate
there may be a Federal policy shift to discontinue community water fluoridation.
In response to the Federal Court ruling referenced above CDPHE issued a community
water fluoridation statement on October 2024. That statement is attached as Exhibit E
to this memo.
Staff is providing an update and information to council on the current state of water
treatment and potable water quality given these recent events.
FINANCIAL IMPACTS:Staff spends 24 hours per week preparing fluoride reports,
conducting fluoride concentration measurements, checking equipment, and filling
equipment with solid fluoride feed stock. Staff spends an additional 160 hours yearly to
perform equipment overhauls and cleaning as recommended by the equipment
manufacturer. Staff spends ~$30,000 annually on the supply of sodium silica fluoride
and spends additional ~$90,000 annually on bleach and coagulants.
ENVIRONMENTAL IMPACTS:Staff produce potable water with the least amount of
environmental impact to the best of their abilities following Colorado Department of
Health and Environment Potable and Clean Water Quality Standards.
ALTERNATIVES:Council can weigh the benefits and risks of a community water
fluoridation program and direct staff to keep or remove community water fluoridation.
RECOMMENDATIONS:Staff requests continued support on future Water Treatment
Facility Improvement Projects to modernize the current treatment facility and maintain
City staff’s ability to provide safe, reliable water treatment and quality potable water to
the public. Staff has no recommendations regarding water treatment, water quality, or
community water fluoridation at this time. Staff follows all CDPHE and EPA guidelines
for public health and safety, Aspen’s potable water is proudly monitored 24 hours a day
7 days a week.
CITY MANAGER COMMENTS:
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ATTACHMENTS:
Exhibit A: Aspen Water Treatment Facility
Exhibit B: Water Treatment Facility Schematic
Exhibit C: 1989 Fluoride Ballot Question Results
Exhibit D: Resolution No. 12 of 2012 and Memo: City Council Fluoridation
Concentration Approval
Exhibit E: CDPHE Statement on Community Water Fluoridation, October 2024
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Cattle
Creek
Maroon
Creek
Leonard
Thomas
Reservoir
Rapid
Mix
Basin 2-Stage
Flocculation Tube Settler
Sedimentation
Basin
Rapid
Mix
Basin
North Clarifier
1-Stage Floc.
South Clarifier
1-Stage Floc.
East ClearwellEast Filters
West Filters West Clearwell
Clearwell
Contact Basin
To Distribution
System
LEGEND
Process & Chemical
Streams
Discharge Streams
Residual Streams
Common Elements
Backwash
Pond
Drying Bed
Overflow to
Castle Creek
Hauled Dried
Solids to
Landfill
Mucked
Out
Solids
Exhibit B: Water Treatment Facility Schematic
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October 14,2024
Statement on Community Water Fluoridation
The Colorado Department of Public Health and Environment (CDPHE)recommends that public water
systems maintain fluoride levels in drinking water at 0.7 milligrams per liter (0.7 mg/L)to protect against
tooth decay.
Cavities are the leading chronic disease among children and adults in the United States,far surpassing the
rates of asthma,diabetes,and hypertension.Recent findings from CDPHE indicate that more than 60%of
Colorado’s third graders have experienced tooth decay,with about half of these children having not
received dental treatment.Poor oral health in children contributes to lower school performance,more
missed school days,behavior problems resulting from untreated oral pain,and preventable oral health
care spending for families and Colorado taxpayers.
Fluoride is a naturally occurring mineral found in nearly all water sources.Similar to other
health-promoting nutrients in foods such as calcium added to milk to protect bones,folate added to
orange juice to prevent birth defects,and iodine added to salt to protect thyroid function,fluoride added
to water protects teeth.
Since 1945,community water fluoridation has been studied hundreds of times by many reputable
scientific organizations for its safety and efficacy in preventing tooth decay.The overwhelming findings of
these studies indicate that fluoride,at the Centers for Disease Control and Prevention (CDC)
recommended level in drinking water,reduces tooth decay by more than 25%,irrespective of other oral
health-protective factors such as brushing,flossing,or visits to the dentist,without posing risks to health
or safety.
Additionally,fluoridation is a cost-effective public health measure,saving $61 in oral health care costs for
every dollar invested in drinking water fortification with fluoride.In fact,each fluoridated water
consumer can benefit from a lifetime of protection from oral disease for less than the cost of a single
dental filling.
In contrast to well-established scientific evidence,on September 25,2024,the United States District
Court,District of Northern California ruled that community water fluoridation at optimal levels poses an
unreasonable risk to public health under the Toxic Substances Control Act (TSCA).In its opinion,the Court
cited the National Toxicology Program's report titled “Fluoride Exposure:Neurodevelopment and
Cognition”,released on August 25,2024,as the basis for its opinion.
The National Toxicology Program report was conducted as an analysis of data from multiple independent
studies examining fluoride exposures well above recommended levels in drinking water,often derived
from research conducted outside of regulated U.S.water systems.The National Toxicology Program report
explicitly stated that “there were insufficient data to determine if the low fluoride level of 0.7 mg/L
currently recommended for U.S.community water supplies has a negative effect on children’s IQ.”
Furthermore,the National Academies of Sciences,Engineering and Medicine reviewed a pre-release draft
of the National Toxicology Program report in 2021 where the report’s authors were advised to clarify that
its conclusions do not apply to recommended fluoride levels in drinking water.The Academies review
stated that “much of the evidence presented comes from studies that involve relatively high fluoride
concentrations and that the monograph cannot be used to draw conclusions regarding low fluoride
exposure concentrations (less than 1.5 mg/L),including those typically associated with drinking water
fluoridation.”
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The District Court’s opinion did not reference the National Toxicology Program report’s admonition against
applying its findings to public policy regarding the recommended level of fluoride in drinking water nor
did the opinion cite compelling new evidence to support changes to the current public health
recommendation regarding fluoride in drinking water.
Because of these circumstances surrounding this ruling, the department’s recommendation for a drinking
water fluoridation level at 0.7 mg/L is not changed. The department’s standing recommendation aligns
with the positions of the U.S. Surgeon General, the Centers for Disease Control and Prevention, the
American Public Health Association, the American Medical Association, the American Association of Public
Health Dentistry, the National Institute of Dental & Craniofacial Research, and the World Health
Organization, among numerous other highly regarded organizations.
Additionally, following the announcement of the Court’s opinion, the American Water Works Association,
the American Dental Association, the American Academy of Pediatrics and the American Fluoridation
Society have each reaffirmed support for optimal community water fluoridation as safe, effective, and
essential to the protection of the public’s health.
CDPHE seeks to align its public health recommendations with the latest scientific research. The facts of
this Court ruling are not sufficient cause to revise the department’s long-standing recommendation to
adjust fluoride levels in finished drinking water to 0.7 mg/L. The department will continue to review new
and emerging research on community water fluoridation and will revise its recommendations only when
supported by the weight of scientific evidence.
The state Dental Director and the Oral Health Unit are able to respond to further inquiries regarding
community water fluoridation and this Court ruling at cdphe.psfluoridationsmf@state.co.us.
Thank you for your partnership in protecting the public’s health.
Ned Calonge, MD, MPH Maryam Mahmood, DMD, MPH Nicole Rowan, PE, ME
Chief Medical Officer State Dental Director Water Quality Control Division Director
Resource contact:jennifer.lansing@state.co.us
CDPHE accessibility statement
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