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Welcome to the first edition of Stormwater News, the
official newsletter of the MPCA’s stormwater program. The newsletter will be
delivered quarterly, and provide:
- Stormwater Manual updates and other guidance
materials
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program and regulatory updates
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research news
- success stories
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funding opportunities
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innovative approaches to permit compliance
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training offerings
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and more …
The newsletter will contain information on municipal,
construction, and industrial stormwater and will replace the Stormwater Manual
newsletter. Subscribers to the MPCA’s municipal stormwater, construction
stormwater, and stormwater manual news lists will be receiving this newsletter four
times a year. Industrial stormwater subscribers will continue to receive a
separate Industrial Stormwater newsletter, which has more in-depth information on that sector.
About the MPCA’s
stormwater programs
The MPCA administers the requirements of the federal
Clean Water Act in addition to its own State Disposal System requirements. At
the MPCA, the Stormwater Program includes three general stormwater permits: the
Municipal
Separate Storm Sewer Permit, the Construction Stormwater
Permit, and the Industrial Stormwater
Permit. Each
program administers a general permit (and in some cases, individual permits)
that incorporates federal and state requirements for Minnesota stormwater
management. Each program also offers guidance and assistance.
Set up your BMPs
before winter starts!
The construction season is coming to a close. Set up erosion
and sediment control measures on your site before the ground freezes, so they offer
protection during winter thaws, rain events, and the spring snow melt. Don’t
risk water quality violations!
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Stabilize
all exposed soils with mulch or other cover and plant seed for early
spring.
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Remove sediment deltas.
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Stabilize
ditch bottoms with appropriate BMPs.
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Clean sediment traps.
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Clean sediment from streets and gutter systems.
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Repair non-functioning BMPs
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Operating in frozen conditions
If construction work is suspended due to frozen conditions,
the site inspections can be suspended too. However, if snow melt or
precipitation causes runoff during the winter months, the inspection and
maintenance schedule must resume within 24 hours after the runoff occurs. If
construction resumes during frozen conditions, inspections must resume 24 hours
prior to resuming the construction and continue while construction is active. Install
erosion and sediment control measures on the same timelines required during
non-frozen conditions, but the installation method and type of BMPs may change.
For example, hydro mulches can’t be used on snow, but straw mulch can. Instead
of staking and trenching in silt fence, use weights to adhere it to the ground
or use rock logs as perimeter control.
After the Census Bureau released its 2010 data, MPCA
identified several communities and public facilities that appeared to meet the
criteria for MS4 permitting. MPCA staff worked with these entities and
determined that 25 will receive coverage under the MS4 permit.
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The City of Bayport is
one of 25 communities that will receive coverage under
the MS4 permit based
on results of the 2010 Census.
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Over the past 18 months, MPCA staff have provided technical
assistance and information to these 25 new applicants as they develop
stormwater pollution prevention program (SWPPP) documents. The MPCA also partnered
with University of Minnesota Extension to present workshops to the new applicants on general stormwater management topics and a short course
specifically tailored to townships.
Several pages have been created or updated since the most
recent newsletter, and several sections of the manual are undergoing updates
this fall.
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Pretreatment—
Section was updated and includes general information for pretreatment settling
devices, pretreatment screens, and pretreatment vegetated filter strips.
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Infiltration practices (includes infiltration basins,
infiltration trenches, underground infiltration, and dry wells) — The design, construction, and operation
and maintenance pages have been updated. New pages address types
of infiltration, case
studies, and information
on collecting and interpreting soil borings.
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Stormwater and rainwater harvest and
use/reuse — Section in development and scheduled to be completed this
fall.
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Construction
stormwater — Section reorganized and includes information on erosion
prevention practices and sediment
control practices. Each of these sections is undergoing development and
should be completed this fall. We’ve also begun adding photo
galleries for construction practices.
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Stormwater infiltration, contaminated soils,
and groundwater — See two new pages: Contaminated sites and
stormwater infiltration and Screening
assessment for contamination at potential stormwater infiltration sites
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Pollinator-friendly BMPs — Find information on
designing and implementing pollinator-friendly stormwater BMPs.
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Virtual tours
— See links to Minnesota organizations with virtual tours or good maps of their
stormwater BMPs.
Stormwater runoff captured by an infiltration best
management practice (BMP) must infiltrate into the underlying soil within 48
hours. Properly designing an infiltration BMP therefore depends on obtaining
accurate information on soil infiltration rates. Getting the soil infiltration
rate wrong at a site can lead to increased cost and likely failure of the BMP.
Unfortunately, soils vary greatly in their infiltration
properties, even within a specific soil type over very short distances.
Ideally, soil infiltration rates are determined
in the field using an infiltrometer, permeameter, or other appropriate
method. More often, borings are utilized to identify soil type and an infiltration
rate is associated with that soil type.
The Minnesota Stormwater Manual contains a
new page discussing the collection and interpretation of soil borings for
infiltration BMPs. The manual includes the following caution:
Objectives
for collecting soil borings for stormwater infiltration practices differ from
objectives for collecting borings for structural engineering purposes.
Identification of low permeability or restrictive layers in soil are critical
to proper design and construction of infiltration practices.
The new manual page discusses important considerations for
collecting and interpreting soil borings, number to collect, what to do when
sample recovery is low, how to identify a confining layer, and more. The page
includes sample boring logs, summary tables, images, references, and links to
additional information. If you use soil borings in the design and construction
of stormwater infiltration BMPs, the new manual page should be valuable to you.
Since the Minnesota
GreenCorps program began in 2009, 30 GreenCorps members have served in the
“Green Infrastructure: Stormwater” track at host sites throughout Minnesota.
Cities, watershed districts, universities, and nonprofit organizations have
benefited from the work of GreenCorps members, several of whom have enter the
workforce with their host sites or as stormwater managers in other capacities.
GreenCorps members help organizations lead projects that
they couldn’t have otherwise implemented and work with regulated municipalities
to go above and beyond requirements or improve their communities. This year,
there are three members whose main focus is stormwater. Erica Strom is working
with the City of Duluth and the Regional Stormwater Protection Team to develop
programs to encourage responsible salt application and chloride pollution
reduction. Shanti Penprase is supporting the Freshwater Society’s expansion of
its popular Master Water Stewards program to a statewide audience. Leah Weston
is helping the City of Faribault inventory stormwater practices within city
boundaries and conduct outreach on stormwater issues.
If your organization may be interested in employing a
Minnesota GreenCorps member, go to the MPCA web
site and sign up to be notified about future opportunities.
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 Minnesota has recently experienced a surge in solar-farm construction
as renewable energy becomes more popular. The MPCA has developed guidance
on stormwater management to address the unique characteristics of solar farms
and to help designers, engineers, and contractors comply with the MPCA’s
Construction Stormwater General Permit requirements. The agency also offers
additional stormwater
and landscape guidance for solar farms. For more information, call the MPCA
at 651-296-6300 or 1-800-657-3864 and ask for Construction Stormwater staff.
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 The Stormwater Program is involved in several research
projects that look at pollutant removal by stormwater BMPs and other stormwater management questions. The projects
include:
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Iron-enhanced filtration — In
partnerships with two cities and a watershed district, we’re examining the
effectiveness of five iron-enhanced stormwater treatment systems: two sand
filters, a biofiltration system, and two detention ponds retrofits.
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Infiltration monitoring — The MPCA is
partering on two projects that monitor infiltration systems at four sites to assess
pollutant transport and removal within the BMP and in the unsaturated soil zone
underneath. The sites include surface and underground infiltration practices.
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Daphnia ecotoxicogenomics method
development and calibration — Researchers are investigating the viability and
value of using a daphnia-based transcriptomics tool as part of MPCA's water
quality monitoring efforts.
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Contaminants of emerging concern (CECs) in stormwater
— MPCA and several partners are investigating CECs and associated toxicology in
stormwater conveyances and iron-enhanced sand filters in the Twin Cities area.
Researchers are measuring more than 300 commercial/industrial chemicals and the
effectiveness of full-scale iron-enhanced sand filters at mitigating their
impact.
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Infiltration in roadside swales: Long-term
field testing prototype — MPCA and MnDOT are prototyping a method to assess
the long-term infiltration performance of swales in natural conditions at
various scales.
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Stormwater research priorities and pond
maintenance — The MPCA, serving as the state’s technical liaison, is
assisting the University of Minnesota in
looking for ways to improve stormwater pond maintenance and performance. This
project will also produce a ten-year framework of stormwater research needs,
and provide for education and training to disseminate the results.
When appropriate, data from these projects will be
aggregated for analysis with Twin Cities area data available from other sources
to achieve broader representation. These projects are possible through
much-appreciated partnerships and Clean Water Funds and, for one project, an
EPA grant. As each is completed, MPCA will provide summaries in this
newsletter, with full reports available through the Stormwater Program web site
and manual. For more detailed information on these projects, visit the Minnesota
Stormwater Manual.
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The industrial stormwater program regulates 29 industrial
sectors, including manufacturers, recyclers, transporters, landfills, and
wastewater treatment plants. The program offers guidance, assistance, and
regulatory compliance to regulated industries, and even offers facility-specific
stormwater management suggestions from their engineer. The program has created
several short YouTube training videos, guidance manuals, and a self-audit
“inspector’s checklist” document. To learn more or to view these guidance
materials, go to the industrial
stormwater home page.
This summer, the MPCA’s Industrial Stormwater Program worked
with interns who spent part of their internship experience working with
regulated stormwater facilities. Additionally, the Minnesota Technical
Assistance Program highighted this year’s interns, whose focus included waste
reduction, stormwater conservation, and lean manufacturing. Read all about
these developments, as well as the latest about the Nonmetallic Mining (MNG49)
permit update in the September
2016 Industrial Stormwater News quarterly newsletter.
Marni Karnowski is
Section Manager for MPCA's Municipal Stormwater Program, which is responsible
for permitting, compliance and enforcement, assistance, communications, TMDL
implementation, and research associated with Municipal Separate Stormwater
Sewer Systems (MS4s) and construction stormwater sites.
Ryan Anderson
supervises the research, engineering, and outreach unit; staff include David
Fairbairn, Mike Findorff, Anne Gelbmann, Paul Leegard, Logan Quiggle, Todd
Smith, and Mike Trojan
Tanya Maurice
supervises the construction stormwater unit; staff include Dave
Bodovinitz, Brandon Dahl, Amy Delbecq, Jim Dexter, Paul Erdmann, Roberta
Getman, Nicholas Nistler, and Jeremy Sanoski.
Duane Duncanson
supervises the municipal stormwater unit; staff include Scott Fox, Brian Green,
Megan Handt, Cole Landgraf, and Joshua
Stock
Over the past year, a lot of new information has been added
to the Minnesota Stormwater Manual. The MPCA hired consultants to update
guidance on pretreatment, infiltration, construction stormwater, and harvest
and re-use. MPCA staff will be setting up a series of webinars on this new
guidance. Our first webinar on infiltration will be on Thursday, December 8 at
1:30 p.m. Save the date!
If you have questions about or suggestions for this newsletter, contact Anne Gelbmann, MPCA-St. Paul, 651-757-2384
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