MINUTES
COLORADO MONITORING FRAMEWORK
NUTRIENT WORKSHOP
BROWN AND CALDWELL
1527 Cole Blvd, Suite 300, Lakewood
Crestone Training Room
March 17, 2015
9:00 a.m. – 2:30 p.m.
Setting the Stage
Sarah Reeves introduced the workshop and everyone introduced themselves. Sarah reviewed the
desired outcomes of the workshop, which were included in the agenda.
1. Reinvigorate CMF commitment to leading the development of flexible and attainable
alternatives to Regulation 31.
2. Understand the Division’s vision for using Regulation 85 data to implement Regulation 31
standards.
3. Prioritize tools/approaches to achieve an alternative to the interim values in Regulation 31.
4. Draft a schedule and actions to develop a flexible nutrient implementation/policy framework.
Implementation of nutrients is really data driven and data collection can be challenging. Warren
Mesloh from the North Front Range Water Quality Planning Association (NFRWQPA) and Ginny
Johnson from Colorado Springs Utilities spoke briefly about their organization’s challenges regarding
data collection and availability.
Prior to the workshop, Warren touched base with the NFRWQPA members about data submittal for
Regulation 85. He found that, out of the 42 SAP certifications in their membership, 32 entities have
their data submitted, reviewed and accepted (for 2013). Eight entities do not have their data
submitted. The process for 2013 data submittal was described as “arduous.” Agencies/Utilities
faced about $6000 on average to comply with Reg 85 monthly sampling and reporting once a year.
The data submittal form itself was also complex.
Ginny started out by expressing her appreciation for the AF CURE group and the fact that members
are working together to sample locations along both Fountain Creek and the Arkansas River. It is
very helpful to work as a watershed group, with everyone collaborating. The AF CURE watershed is
large, so it is challenging to find out where the nutrients are coming from and to get a picture of how
the watershed is working. Springs Utilities uses USGS for sampling because they haven’t been able
to dedicate internal resources to that task. Their budget was cut this year and now they can’t sample
at the tributaries and where nutrients might be naturally sourced.
Nicole Rowan from the Water Quality Control Division (WQCD) stated that their environmental data
group has been working with 400 facilities statewide, of which 363 have submitted their data for
2013. They are trying to map out the coverage they have gotten from the Regulation 85 sampling to
see if there are any gaps in spatial coverage. To date, 13% of dischargers have already submitted
their 2014 data. Last year it took until fall to process all of the data but this year they are hoping to
process the data much earlier. They would like these data to inform the discussion with the WQCD
and Water Quality Control Commission (WQCC) this fall.
The President of the Colorado Water Quality Monitoring Council (CWQMC), Linda Chynoweth, said
that the Data Sharing Network (DSN) is their main focus. The DSN is not changing their template this
year and they are willing to help new users with this template.
Sarah Reeves noted that we really are sharing the same issues and challenges – collecting data,
coordinating data collection, delegating resources, and allocating time and resources to collect data.
WQCD Statewide Nutrient Approach and Coordination with CLEAN
Andrew Ross from the WQCD presented on the state’s plan for Regulation 85 data and use of the
eRAMS model for nutrient standards/implementation. eRAMS is a scalable GIS platform, open
source, and owned by the State of Colorado. They are encouraging third party module development
to grow the platform. The WQCD is currently working on a contract with CLEAN/Colorado State
University to analyze the Regulation 85 data in a SWAT (Soil Water Assessment Tool) model. SWAT
models have been peer reviewed and CSU has a lot of experience working with this model. They are
trying to determine what the current nutrient conditions are in order to quantify expected
improvements in nutrient concentrations/loads from implementation of the Regulation 85 permit
limits. They are also looking into what management options are available for nonpoint contributions,
especially agriculture, and the expected improvements instream from such controls.
Andrew opened up the current eRAMS model (www.Erams.com/cdphe). Right now it functions as a
GIS webpage. It displays all of the data points collected through STORET and USGS. You can search
for a specific location and see their Regulation 85 data from 2013. There have been issues with the
naming conventions of some sites. This will be a foundation of their SWAT model.
Q – How does the eRAMS model work together with the CLEAN effort?
A - CLEAN is trying to work on agricultural BMPs, stormwater BMPs, wastewater treatment,
streambank stability, greywater, and nutrient trading. The WQCD is not building this model for
trading, they are trying to resolve simple questions with the Regulation 85 data. Looking at trading
options could be a possibility in the future, though.
Q – How does eRAMS consider nonpoint sources?
A - eRAMS is pulling all data from STORET and USGS, including some groundwater data. There are a
lot of ag/groundwater data that weren’t taken into account before in the SPARROW model. The plan
is to fill the gaps with information from some other agricultural projects that are on-going.
Q – How is water management incorporated into the model?
A - eRAMS will be able to incorporate water management (diversions, timing, etc.) in the future.
Q - Can someone peer review this model? Nitrogen is especially difficult to model.
A - Once the model is finished later this summer, Andrew Ross will be presenting it to the Water
Quality Forum and other interested organizations.
Q - How is the WQCD going to use this model?
A – The WQCD needs to know if Regulation 85 permit limits are going to help us achieve the
Regulation 31 interim values in stream. We won’t use the model to predict impairment, but when we
get to the TMDL phase we may use this model. The SWAT model could be used for permitting, but
after 2022 and only if there is consensus and buy-in. This is a watershed based model; the most it
can do is a mass balance. If you use a model for permitting, you will want a more site-specific model.
This model will give an idea of sub-basin nutrient levels, but not for a specific location.
Q – Can this model be used to develop site-specific standards?
A - No, this model cannot be used as a tool to develop site-specific standards. Someone could try to
build a smaller-scale model, because it is an open source program, but the WQCD isn’t trying to do
that. Right now the WQCD is trying to understand if we are meeting the Regulation 31 interim values
in stream, what the data look like, and how we could use the information.
Q - Could the model be developed to be more site-specific and could we provide this information to
the WQCD?
A - Yes, you can further develop your specific location and share that information with others.
Q – How is the WQCD considering population growth?
A – The Division hasn’t yet figured out what we will be discharging in 2022 conditions (i.e., at the
expected population in 2022). After we understand the 2022 condition, we will focus on post-2022.
Q – Ultimately, we are concerned with each location. Why is this state-wide modeling important to
the WQCD?
A - It is important for the nonpoint source world – particularly agriculture. This will help us get a
baseline so we are able to monitor our progress in reducing nutrients. Agriculture is “exempt” from
the Clean Water Act. The WQCD could regulate ag if they wanted to, but we need to figure out what is
actually happening in the environment with nutrients from agriculture first. Right now there are
conflicting data. Where to go with this effort is still a question. Whether the state requires BMPs is up
for debate. Not sure if there will be enough political will. SPAN (South Platte Agriculture Nutrient
Committee) is working on this effort. Ag producers feel like there is nothing more that they could do
to control/manage nutrients.
Key Dates:
June 23 – Triennial Review Stakeholder Meeting 3 (1:30 CDPHE)
August 17 - Triennial Review Stakeholder Meeting 4 (1:30 CDPHE)
End of July – Notice for the Regulation 85 Triennial Review Informational Hearing will be posted.
September 9 – WQCD’s memorandum with recommendations for Regulation 85 Triennial Review
Informational Hearing due to the WQCC. Would like other proposals/ideas submitted by this
date.
September 30 – Public comments due to the WQCC.
October 13 – Regulation 85 Triennial Review Informational Hearing.
NACWA’s Review of Nutrient Permitting Methods
The National Association of Clean Water Agencies (NACWA) reviewed the suitability of using EPA’s
Technical Support Document (TSD) for Water Quality-Based Toxics Control (dated March 1991) for
nutrient permitting. In the absence of specific guidance for nutrient permitting, the EPA was
suggesting using the TSD for nutrient permitting in their training sessions. NACWA’s concern is that
the TSD is for toxics control, not for nutrients, which have more of a chronic impact. Brown and
Caldwell was selected to review the TSD for NACWA to provide a recommendation about the
appropriateness of applying the various elements of the TSD to nutrient permitting. Three
overarching themes came out of the report:
1. Provide additional flexibility in how waste load allocations are derived.
2. Modify WLA/WQBEL calculation methods.
3. Consider treatability limitations - which options are feasible?
The following is a list of the recommendations from the NACWA report.
 In order to provide additional flexibility in how waste load allocations are derived, we need to
emphasize loads rather than concentrations and response variables rather than water
quality endpoints. There are many examples of successful nutrient-response linkages
including in California, Montana, and Florida.
 The use of bioconfirmation to inform WLAs - to look at the biological condition and nutrient
response variables. Ohio has proposed a Nutrient Assessment Protocol that includes
bioconfirmation. EPA has issued guidance on bioconfirmation, but they still want a numeric
standard. Instead of just looking at nitrogen and phosphorus, it is important to look at what
are we really trying protect in the receiving water-body.
 Allowing watershed-base permitting - to tailor goals to a basin, encourage equity among
resources (energy consumed), and consider cost-effectiveness.
 Considering preferential nutrient controls and looking at what is the limiting factor for algal
growth.
 Considering tiered uses/criteria - what are our expectations for water-bodies and what is
realistic?
 Considering the use of longer averaging periods for nutrients. Using the right averaging
periods is critical and very different from what is appropriate for toxics. The averaging period
is used repeatedly in WLA/WQBEL calculations. A daily limit for nutrients is almost obsolete
because they don’t respond on that small of a timescale. A monthly limit or longer is more
realistic.
 Setting a more reasonable allowable frequency of exceedance. For example, Florida’s
numeric nutrient criteria for lakes and reservoirs uses an annual geometric mean to be met
2 out of 3 years. The Chesapeake Bay TMDL uses WLAs based on annual hydrology with a 1
in 10 exceedance
 The probability basis for nutrients should be less conservative because nutrient impacts are
different than toxic impacts. NACWA met with EPA and explained that using the correct
averaging period and considering the probability basis is still protecting their watershed. A
few examples were presented. One example uses a target distribution that will “rarely”
exceed the WLA (95th percent probability basis). Using this distribution, they are only
expected to exceed the critical condition 1 month in 18 months.
 Considering empirical models - instead of assuming a statistical distribution, you can use
your data to make an empirical model. Not all data are log normal.
 The TSD review generally focused on development of WLAs/ WQBELs; however, treatability
limitations also need to be considered. Technologies should be reasonably cost-effective and
more sustainable technologies might not provide the lowest treatment levels.
Variances might be seen as brute force method, but sometimes it is necessary to acknowledge that
a permit limit is necessary for that water body, but we can’t feasibility meet it. EPA seems to really
like variances.
A hybrid water quality and technology-based permitting approach is also a good option.
Since this review, NACWA presented a webinar to the Association of Clean Water Administrators
(ACWA0 and met with EPA a couple of times. It was positively accepted by the EPA and they have
modified their training materials. EPA is expecting the states to take charge in developing their own
nutrient framework/guidance.
Breakout Session – Prioritizing Alternatives
Where can CMF make a difference? What is our priority? Attendees split into groups and prioritized
some of the alternatives that came from the NACWA report as well as other options that had been
identified in the Nutrient Task Force.
After the breakout sessions, the group came back together and people from each breakout reported
out. Conversations focused on:
 Looking at nutrients collectively.
 The watershed approach may be difficult, but how can we start looking at things holistically?
 Data is going to drive a lot of this activity.
 Setting permit limits seemed very far out, so they were given a lower priority.
 Connecting standards to permitting.
 Re-approaching the chlorophyll a standards
 Re-thinking is necessary– we need to get over institutional thinking and implement a new
thought process.
Based on ranking of focus areas, the top five were:
 Bioconfirmation
 Preferential Nutrient Control
 Modify WQBEL Method (use of appropriate averaging periods, probability basis, and critical
conditions)
 Adaptive Management
 Trading and Offsets
Note that site-specific modeling wasn’t specifically called out or listed in the topics discussed
because this is already a focus of the CMF.
South Platte Segment 15 Nutrient Model
Dr. Bill Lewis presented on the South Platte Water Quality Model. Dr. Lewis was hired by Metro
Wastewater Reclamation District (MWRD) in the late 1980s to develop a nutrient model because
MWRD was getting the blame for noncompliance in Segment 15 of the South Platte. As part of that
initial effort, in order to understand photosynthesis and oxygen demand throughout the day, hourly
grab samples were collected. That effort is continuing 25 years later! Last year, segment 15 did not
even approach the instream standards.
Over the years, they have added to the model to understand nutrients and temperature. MWRD is
interested in the mass balance of water and regulated constituents, and in dynamics (the transport
and transformation of water constituents). They divided the model into river segments that are about
a 10th of a mile. The water volume changes significantly throughout each segment because of
groundwater flows. The South Platte sees about 4 cfs per mile of gain from groundwater.
The model was developed through looking into transport and transformation. Downstream flow is
calculated using upstream flows, tributary flow, effluent, ditch withdrawals, and seepage. It is
calibrated through checking gage data, and ditch and tributary records. Biological transformation is
determined through redox changes, assimilation by organisms/bacteria, and synthesis. Abiotically,
transformation occurs through sedimentation, entrainment, and adsorption. These data are
calibrated through weekly monitoring at 15 sampling stations and some special 24-hr studies.
The model is applied to permitting conditions (low flow, max capacity), longitudinal changes in
standards (ammonia and metals), and longitudinal changes in temperature, substrate, velocity and
concentrations. For example ammonia is less stringent at the discharge because of the low pH, and
the critical point for ammonia is at some location downstream.
When looking at the critical conditions, the low flow condition is near 10 cubic feet per second (cfs).
Therefore, using the river water for dilution does not help MWRD and their permit limits are set at the
standard.
The model has shown that peaks in phosphorus can be attributed to storms when particulate
phosphorus is suspended. All of the tributaries and upstream flows would not be in compliance with
the Regulation 31 interim values. Groundwater sampling shows that there is great variability of
nutrients in groundwater. Almost all of the groundwater samples are over the stream standards. If
upstream is noncompliant, the discharger has to meet the standards at the point of discharge.
Looking at the effluent chemistry, total phosphorus (TP) has been reducing since 2009 as well as
total inorganic nitrogen (TIN). It is very important to not have short term standards for nutrients –
they are meaningless. The data vary significantly from year to year and throughout the year.
The chlorophyll concentrations are very low because algae does not grow on the river beds – they are
carried away with sediment. The biggest concern is the lakes and reservoirs downstream.
This is a very data intensive process. What is the minimum sampling program? Consistent bi-weekly
sampling would be a good compromise. You can also narrow the constituents you are monitoring
(TN, TIN, TP).
WERF Nutrient Modeling Toolbox – Boulder Creek
Clifton Bell gave an update on the status of the WERF Nutrient Modeling Toolbox project on Boulder
Creek. This project is funded jointly by WERF and CMF. Clifton thanked CMF for our support. The
projects goals are to improve the understanding of nutrient-response relations in Boulder Creek, to
determine the viability of site-specific standards, and to test the application of the Nutrient Modeling
Toolbox.
The general process to develop a nutrient model includes developing a conceptual model, choosing
ecological response endpoints, selecting a process-based model, developing the model, calibrating
the model, applying it to management scenarios, and testing with water quality data.
Boulder Creek starts in the mountains, travels through the city, and then to the high plains. The
creek changes quite a bit through this area of interest. There are inputs from stormwater,
wastewater, and agriculture. The local advisory team determined that DO, pH, chlorophyll a, and
benthic macroinvertebrates were the parameters of interest.
The City of Boulder had a strong monitoring program, with data going back to the 1980s (with the
exception of periphyton). They applied a model selection tool which provided a list of models that
would be the most appropriate. The biggest decision they had to make was whether to use a
dynamic or a steady-state model. They chose a steady-state model because it was difficult to model
algal growth and scouring and also because the data available better fit a steady-state model. The
model includes 22 segments (a total of about 31 kilometers). It was calibrated to 2013/2014 data.
They constructed a water balance to model flows.
The project team determined that shade is an important factor. There is more shade in the canyon,
some shade in the city, and very little shade in the plains. Sloughing/scour is a very important factor
and is challenging to model. The water velocities are a key factor in determining when/where algae
accumulation and removal is expected to occur. When you calibrate to a high algal condition, there is
a low ammonia condition. The highest biomass of algae occurs before snowmelt.
The next steps are how we can use this model to guide nutrient management and to develop site
specific standards.
Opportunities for WERF Next Steps
The group didn’t discuss possible next steps with WERF, as Bret Linenfelser was on a call to discuss
those options with WERF during this portion of the workshop.
We have the eRAMs model which helps us determine general statewide nutrient concentrations, the
Segement 15 model which is calibrated very well with lots of data, and the WERF model which
includes algal growth. We also know it is important to consider the farfield effects of nutrients. In the
urban South Platte, this could be Barr Lake and Milton Reservoir and in the Fountain/Arkansas basin
this could be John Martin Reservoir. It wouldn’t make sense to use several different models to
determine the farfield effects. We already have developed several tools – how can we add on to
these tools and use them together?
What does the sampling scheme look like to run these models? CMF is looking at collecting data – is
there an active data collection effort for periphyton? No, not right now - it is challenging to collect
periphyton data. Two or three hydrologically different years would be preferred to have a
representative dataset for periphyton.
Breakout Session – Developing Action Plan
Attendees broke out into groups again and focused on one of the 5 topics identified in the first
breakout session:
 Bioconfirmation
 Preferential Nutrient Control
 Modify WQBEL Method (use of appropriate averaging periods, probability basis, and critical
conditions)
 Adaptive Management
 Trading and Offsets
The breakout groups discussed the topic and began to add detail around actions needed to be able
to implement that topic (action description, stakeholders, schedule, deliverables, and ballpark
costs). This effort will be used by the Nutrient Task Force as a starting point for further development
of CMF’s plans.
ATTENDANCE
COLORADO MONITORING FRAMEWORK
NUTRIENT WORKSHOP
March 17, 2015
9:00 a.m. – 2:30 p.m.
Name
Agency/Entity
Email
Phone
X
Linda Chynoweth
Aurora Water
lchynowe@auroragov.org
303-739-7391
X
X
Jill Piatt Kemper
Sean Lieske
Sherry Scaggiari
Zach Shelley
Aurora Water
Aurora Water
Aurora Water
Big Thompson
Watershed Forum
BMW Association
FRICO
City of Boulder
City of Brighton
jpiatt@auroragov.org
slieske@auroragov.org
sscaggia@auroragov.org
zshelley@btwatershed.org
303-739-7390
303-859-4411
303-739-6767
970-613-6163
lrink@uos.net
303-204-4164
linenfelser@bouldercolorado.gov
jarchuleta@brightonco.gov
303-413-7355
303-655-2171
City of Brighton
CAPA CO Wheat
Colorado Livestock
Assn
Colorado Livestock
Assn
Law Firm of Connie
H. King, LLC
Centennial WSD
eburke@brightonco.gov
traxler.randy@gmail.com
bhammerich@coloradolivestock.org
303-655-2084
970-554-1567
970-378-0500
abaker@cwsdhrmd.org
303-791-2185
Centennial WSD
Clear Creek County
CSU
Colorado Corn
Growers
Erie
Fort Carson
tgrotheer@cwdhrmd.org
bweaver@co.clear-creek.co.us
vjohnson@csu.org
msponsler@coloradocorn.com
303-791-7181
303-679-2455
719-668-4375
City of Fort Collins
City of Fort Collins
Fountain Sanitation
District
Greeley Water &
Sewer
Greeley Water &
Sewer
Greeley Water &
Sewer
Greeley Water &
Sewer
strong@fcgov.com
cwebb@fcgov.com
fsdmanager@fsd901.org
970-416-2325
970-221-6231
719-382-5303
Zach.dahlgren@greeleygov.com
970-350-9869
Michael.Schoenberg@greeleygov.com
970-350-9368
Dennis.Schump@Greeleygov.com
970-350-9362
colleen.young@greeleygov.org
970-350-9846
Laurie Rink
X
Bret Linenfelser
Juliana Archuleta
X
X
Ed Burke
Randy Traxler
Bill Hammerich
Nolan Stone
X
Connie King
X
Al Baker
X
X
X
Tim Grotheer
Berten Weaver
Ginny Johnson
Mark Sponsler
John Mays
Eric Dunker
X
Susan Strong
Carol Webb
Jim Heckman
X
Zach Dahlgren
Mike Schoenberg
Dennis Schump
X
Colleen Young
connie@chkinglaw.com
jmays@erieco.gov
Eric.w.dunker.ctr@mail.mil
JDS Hydro/WWSD
City of Lafayette
Leonard Rice Engs
(BHCCSD, CCBWQA)
City of Louisville
L/E WWTP
L/E WWTP
L/E WWTP
L/E WWTP
Longmont
dschwenke@jdshydro.com
mickf@cityoflafayette.com
katie.fendel@LREWater.com
719-227-0072
patf@louisvilleco.gov
mgardner@englewoodgov.org
smustain@englewoodgov.org
prussell@englewoodgov.org
dstowe@englewoodgov.org
kathryne.marko@ci.longmont.co.us
303-335-4783
303-762-2605
303-762-2539
303-762-2617
303-762-2606
303-651-8906
cal.youngberg@cityoflongmont.co.us
Greg.Dewey@cityofloveland.org
Michael.mccrary@cityofloveland.org
Fred.linton@coors.com
wicklund@pcisys.net
303-651-8399
970-962-3717
jfkendrick@q.com
719-488-6831
jdorsch@mwrd.dst.org
lhollander@mwrd.dst.co.us
awoodis@mwrd.dst.org
warrenmesloh@NFRWQPA.org
sstanley@northglenn.org
RMuzzy@ppacg.org
303-286-3368
X
Jim Dorsch
Lisa Hollander
Amy Woodis
Warren Mesloh
Shelly Stanley
Rich Muzzy
Longmont
Loveland
Loveland
MillerCoors
Monument
Sanitation District
Monument
Sanitation District
MWRD
MWRD
MWRD
NFRWQPA
Northglenn BDC WA
PPACG
X
X
X
X
X
X
Nancy Keller
Scott Eilert
Jim Quam
Drew Ackerman
Stephen Ellis
Barb Lilley
Pueblo
Pueblo West Metro
Pueblo West Metro
RESPEC
SACWSD
SACWSD
nkeller@pueblo.us
seilert@pwmd-co.us
jquam@pwmd-co.us
Drew.ackerman@respec.com
sellis@sacwsd.org
blilley@sacwsd.org
Eric Marler
Greg Smith
Ken Watt
David Meyer
Mark McCormack
emarler@suncor.com
gsmith@usgs.gov
303-227-7524
303-236-6945
dmeyer@cityofwestminster.us
mark@wwsdonline.com
303-658-2376
719-955-0548
sreeves@brwncald.com
cbell@brwncald.com
303-239-5411
aneuhart@brwncald.com
trstone@brwncald.com
aimee.konowal@state.co.us
Andrew.ross@state.co.us
Nicole.rowan@state.co.us
Arne.sjodin@state.co.us
303-239-5429
303-239-5486
303-692-3530
X
X
X
X
Doug Schwenke
Mick Forrester
Katie Fendel
Patrick Farrell
Mary Gardner
Steve Mustain
Phil Russell
Dennis Stowe
Kathryne Marco
Cal Youngberg
Greg Dewey
Mike McCrary
Fred Linton
Mike Wicklund
Jim Kendrick
X
X
X
X
X
X
Sarah Reeves
Clifton Bell
Suncor Energy
USGS
USGS
City of Westminster
Widefield Water and
Sanitation District
Coordinator
Brown and Caldwell
X
X
Andrew Neuhart
Tammy Stone
Aimee Konowal
Andrew Ross
Nicole Rowan
Arne Sjodin
Brown and Caldwell
Brown and Caldwell
WQCD
WQCD
WQCD
WQCD
X
X
303-955-9589
303-277-5701
719-481-4886
303-286-3240
970-962-2785
303-450-4067
719-471-7080
x109
719-553-2894