HomeMy WebLinkAbout2015-04-20 ENR Packet
AGENDA
CITY OF MAPLEWOOD
ENVIRONMENTAL AND NATURAL RESOURCESCOMMISSION
Monday,April 20, 2015
7p.m.
Council Chambers -Maplewood City Hall
1830 County Road B East
1.Call to Order
2.Roll Call
3.Approval of Agenda
4.Approval ofMinutes:March 26, 2015
5.New Business
a.Amendments to the Stormwater Management Ordinances and Standards:
1)Erosion and Sedimentation Control (Chapter 18, Article III)
2)Stormwater Manager (Chapter 18, Article VII)
3)Sewers (Chapter 40, Article II)
4)Maplewood Stormwater Management Standards
6.Unfinished Business
7.Visitor Presentations
8.Commission Presentations
a.Partners in Energy Update –Commissioner Miller
9.Staff Presentations
a.Spring Clean Up –April 18
b.Waterfest –May 30
c.Maplewood Nature Center Programs
10.Adjourn
Agenda Item 4
MINUTES
CITY OF MAPLEWOOD
ENVIRONMENTAL AND NATURAL RESOURCES COMMISSION
7:00 p.m., Thursday,March 26, 2015
Council Chambers, City Hall
1830 County Road B East
1. CALL TO ORDER
A meeting of the Environmental and Natural Resources Commission was called to order at 7:02
p.m.by Chair Trippler.
2. ROLL CALL
Randee Edmundson, Commissioner Present
Absent
Deborah Fideldy, Commissioner
Mollie Miller, Vice Chair Present
Ann Palzer, Commissioner Present
Tom Sinn, Commissioner Present
Dale Trippler,Chair Present
Ginny Yingling, Commissioner Present
Staff Present
Shann Finwall, Environmental Planner
3. APPROVAL OF AGENDA
Staff requested movingagendaitem 7 (Visitor Presentations) ahead of item 6(Unfinished
Business) since there was a visitor at the meeting.
Commissioner Sinnmoved to approve the agenda as amended.
Seconded by CommissionerMiller. Ayes – All
The motion passed.
4. APPROVAL OF MINUTES
CommissionerMillermoved to approve theFebruary 25, 2015, Environmental and Natural
Resources Commission meeting minutes as submitted.
Seconded by CommissionerYingling. Ayes – All
The motion passed.
5. NEW BUSINESS
Republic Services Annual Trash and Yard Waste Performance Review
a.
i.Environmental Planner, ShannFinwall gave the report on Republic Services
AnnualTrash and Yard Waste Performance Reviewand answered questions of
the commission.
ii.Dan Jurek, Division Manager with Republic Services, Inver Grove Heights,
addressed and answered questions of the commission.
March 26, 2015 1
Environmental and Natural Resources Commission MeetingMinutes
The Commission had the following comments:
Where does the City’s yard waste go?
Mr. Jurek responded that yard waste is brought to the SKB Environmental
o
site in Rosemount where it is recycled into compost material.
Can kitchen scraps be added to the yard waste?
Mr.Jurek clarified that kitchen scraps cannot be placed in the yard waste
o
cart. These can be composted at a Ramsey County yard waste site or in a
backyard compost container.
Do the trash trucks have the capability of weighing trash carts so the City can
begin a weighted pay as you throw method?
Mr. Jurek clarified that the RFID chips in the trash carts only allow the City
o
to monitor trash collection dates/times and cart inventory.The technology
for weighing residential trash carts is not very accurate at this time.
Do all of Republic Services’ vehicles use biodiesel fuel?
Mr. Jurek stated yes. However, the company is moving toward
o
compressed natural gas powered trucks.
The Commission complimented the combined trash and recycling flier prepared
by the City’s trash and recycling haulers this year. It was more convenient to have
all of the solid waste information in one place. Next year it would be beneficial to
have more information on ways to reduce waste.
Commissioner Sinn moved to recommend approval of Republic Services’2014Annual Trash and
Yard Waste Report and 2015Work Plan for the City’s residential trash and yard waste collection
system.
Seconded by Commissioner Miller.Ayes -All
The motion passed.
This item goes to the City Council on April 27, 2015.
6.VISITOR PRESENTATIONS
Jenny Eckman, Environmental Science Specialist,Harambee Community Cultures Environmental
Science Magnet School, 30 County Road B East, Maplewood,addressed the commission.Ms.
Eckman is an educator at HarambeeEnvironmental School in Maplewood. Commissioner
Miller’s children attend this school. Ms. Eckman discussed the school’s environmental programs
andopportunities for community partnerships.
Commissioner Mollie Miller stated there is an opportunity for commission members to volunteer to
judge the Energy Fair at the Harambee Community School on April 30, 2015.
7.UNFINISHED BUSINESS
a.2015 ENR Commission Goals –Implementation Strategies
i.Environmental Planner, Shann Finwall gave the report
Chair Trippler asked if the Commission would like to form subcommitteesto work on each of the
goals. The Commission agreed and the following subcommittees were formed: 1) Environmental
Education –Commissioners Miller, Sinn, and Yingling; 2) Urban Agriculture–Commissioners
EdmundsonandMiller; and 3) Stormwater -Chair Trippler and Commissioner Sinn.
All commission members voted ayes all for the three subcommitteesand appointed members.
March 26, 2015 2
Environmental and Natural Resources Commission MeetingMinutes
8.COMMISSION PRESENTATIONS
9.STAFF PRESENTATIONS
a.Earth Hour –March 28, 2015
Staff played a short video on Earth Hour for the public and the Commission.
b.Spring Clean Up –April 18, 2015, 8 a.m. –1 p.m. (Aldrich Arena)
Staff discussed the upcoming Spring Clean Upwhere residents can dispose or recycle
bulky items. It will be held April 18, 2015, from 8 a.m. to 1 p.m.The City will be collecting
food for the Second Harvest Heartland food shelf during the event. The Environmental
and Natural Resources Commissioners are encouraged to volunteer during the event.
c.Urban Agriculture Tour –June 25, 2015
Staff stated that an Urban Agriculture Tour is scheduled for June 25, 2015. Further
information about this tour will be forwarded to the Urban Agriculture Subcommittee in the
near future.
d.Maplewood Nature Center Programs
Environmental Planner, ShannFinwall presentedthe upcoming Nature Center Programs.
For more information contact the Maplewood Nature Center at (651) 249-2170.
10.ADJOURNMENT
Chair Trippler adjourned the meeting at8:38p.m.
March 26, 2015 3
Environmental and Natural Resources Commission MeetingMinutes
Agenda Item 5.a.
MEMORANDUM
TO:
Environmental and Natural Resources Commission
FROM:
Steven Love, Assistant City Engineer
Shann Finwall, Environmental Planner
DATE:
April 15, 2015 for the April 20 ENR Commission Meeting
SUBJECT:
Amendments to the Stormwater Management Ordinances and Standards
Introduction
The Environmental and Natural Resource Commission will consider
to the City Code related to stormwater, erosion control, and ill
Background
A 1987 amendment to the federal Clean Water Act required impleme
comprehensive national program to address pollution from stormwa
was named the National Pollutant Discharge Elimination System (N
NPDES Phase I regulated cities with populations of 100,000 or mo
effect in 2003, regulating cities with populations of 10,000 or
group of approximately 220 entities in Minnesota listed as a sma
NPDES Phase II permit.
The State of Minnesota regulates the disposal of stormwater by a
permit. The Minnesota Pollution Control Agency (MPCA) administe
permits in Minnesota. In turn, the MPCA regulates cities and ot
Municipal Separate Storm Sewer System (MS4) permit. The MPCA ty
permit once every five years. All MS4 cities are required to su
MS4 permit is reissued. In 2013 the City of Maplewood applied f
MS4 permit, with issuance of that coverage on March 17, 2014.
Discussion
As part of the permitting application process the City was requi
make necessary changes to to meet
the requirements of the new permit. The following is a list of
recommended to be revised and a summary of the main changes that are necessary to meet
the requirements of the new MS4 permit:
Chapter 18, Article III Erosion and Sediment Control
Updated language that covers items such as permits and agreemen
o
City will require prior to commencing with land disturbance acti
Updated definitions
o
Updated language for erosion and sediment control plans
o
Detailed lists of items and content required for an erosion and
plans have been removed
This information is subject to change in the future with each n
reissuance of the MS4 permit
New language for the erosion and sediment control plan has been
which states that the erosion and control plans have to meet the
it
Updated language on the approval process for grading permits
o
Chapter 18, Article VII
New language stating the Maplewood Stormwater Management Standa
o
(MSMS) serve as the guiding document for stormwater design withi
Maplewood
Definitions related to Illicit Discharge
o
New language that covers the prohibition of illicit connections
o
inspections, monitoring and testing in response to illicit disch
penalties, and remedies
Chapter 40, Article II - Sewers
Revised language stating that discharges for properties may be
o
illicit discharge
Revised language that allows the City to recover costs, paid by
o
violations (e.g. clean up costs)
Miscellaneous language revisions
o
These changes are shown on the attached City Code sections with
and deletions being stricken (Attachments 1, 2, and 3).
Along with the above changes to the City Code, revisions to the
Management Standards (MSMS) are required to meet the new MS4 per
summary of the main changes to the MSMS that are necessary to me
new MS4 permit:
Maplewood Stormwater Management Standards (MSMS)
New language that states that the MSMS serves as the guiding do
o
stormwater design within the City of Maplewood
s to exemptions
o
control requirements
placement/rehabilitation projects
and are not as extensive as a partial or full reconstruction pro
new or expanded storm sewer system components are included as pa
of the project
Revise the infiltration/volume control requirement from a volum
o
inches over all new impervious portions of a project or all impe
a redevelopment project
This is consistent with rule changes made by Capital Regions Wa
and Ramsey-Washington Watershed Districts
Revised credit given for filtration practices from 70% to 50%
o
This is consistent with rule changes made by Capital Region Wat
and Ramsey-Washington Watershed Districts
New language that covers mitigation provisions when post-constr
o
2
stormwater management projects for water quality treatment canno
effectively met on site
This language includes selection of locations for mitigation pr
Environmental Utility Fund (EUF) for future mitigation projects
New language recognizing the use of National Weather Services (
o
14 rainfall depths and distributions
The use of Atlas 14 rainfall depths and distributions was appro
City Council at the December 19, 2013 council meeting
Revised langue on design data submittal requirement for meeting
o
infiltration/volume control requirements and volume reduction re
during city review of proposed projects
New langue on restrictions for using infiltration systems
o
Revised soils classification table
o
New language describing requirements of a signed maintenance ag
o
private infiltration systems
New language detailing requirements for erosion and sediment co
o
These changes are shown on the attached MSMS with additions bein
being stricken (Attachments 4)
Budget Impact
There are no budget impacts associated with this agenda item.
Recommendation
It is recommended that the Environmental and Natural Resource Co
revisions to the City Code and Maplewood Stormwater Management S
feedback during the meeting. The City Council will hold a publi
changes to the City Code.
Attachments
1. City Code Chapter 18, Article III Erosion and Sediment Control
2. City Code Chapter 18, Article VII Storm Water Management
3. City Code Chapter 40, Article II - Sewers
4. Maplewood Stormwater Management Standards (MSMS)
3
Attachment 1
-
[5]
ARTICLE III. EROSION AND SEDIMENTATION CONTROL
Sec. 18-141. Purpose.
Sec. 18-142. Scope.
Sec. 18-143. Definitions.
Sec. 18-144. Erosion and sediment control plan.
Sec. 18-145. Review of plan.
Sec. 18-146. Modification of plan.
Sec. 18-147. Escrow requirement.
Sec. 18-148. Enforcement; penalty.
Secs. 18-149—18-175. Reserved.
Sec. 18-141. Purpose.
The purpose of this article is to control or eliminate soil erosion and sedimentation within the city.
This article establishes standards and specifications for conservation practices and planning activities
which minimize soil erosion and sedimentation.
(Code 1982, 11.5-1)
-
Sec. 18-142. Scope.
Except as exempted by the definition of the term "land disturbance activity" insection 18-143, any
person, state agency, or political subdivision thereof proposing land disturbance activity within the city
the approval of
a grading permit, submit an erosion and sediment control
shall apply to the city for
plan, and sign an erosioncontrol compliance agreement. No land shall be disturbed until the erosion
. No land shall
control compliance agreement has been signed,the erosion and sediment control plan
be disturbed until the planis
has beenapproved, installed erosion and sediment control BMP’s
the city and conforms
have been inspectedby City staff, and the grading permit has been issued.
The erosion and sediment control planshallconformto the standards set forth in this articleand meet the
requirements for erosion and sediment control and waste controls in accordance with the MPCA’s
Construction Stormwater Permit as defined in section 18-143.
(Code 1982, 11.5-2)
-
Sec. 18-143. Definitions.
The following words, terms and phrases, when used in this article, shall have the meanings ascribed
to them in this section, except where the context clearly indicates a different meaning:
1
Best Management Practices or BMPs means practices to prevent or reduce the pollution of the
stormwater runoff, including schedules of activities, prohibition of practices, and other management
practices, and also includes treatment requirements, operating procedures and practices to control plant
site runoff, spillage orleaks, sludge, or waste disposal or drainage from raw material storage.
BMP Manualmeans the MPCA’s most current Stormwater Best Management Practices Manual.
Developermeans a person, state agency, or political subdivision thereof engaged in a land
disturbance activity.
means the Ramsey Soil and Water Conservation District organized
District
and operating under Minn. Stats.ch. 40.
Erosionmeans any process that wears away the surface of the land by the action of water, wind, ice,
theof man and nature
or gravity. Erosion can be accelerated by
human and/or naturalactivities.
Erosion and sediment control planmeans a document containing therequirements ofsection 18-144
and
that, when implemented, will decrease soil erosion on a parcel of land being developed, as well as
off-site sediment damages.
and
and sediment control practice specificationserosion and sediment
Erosion
mean the management procedures, techniques, and methods to
control practices
control soil erosion and sedimentation as officially adopted by the district.
control
compliance agreement means a document stating that the all BMPs will be installed and inspected prior
to any land disturbing activities, the BMPs will be maintained throughout the entirety of the project, and
that the project site will be stabilized prior to granting a Certificate of Occupancy and/or release of any
grading permit escrow.
Land disturbance activitymeans land change that may result in soil erosion from water or wind and
county
the movement of sediments into or upon waters or lands of the city, adjacent cities or any
adjacent properties, including clearing, grading, excavating, transporting and fillingof land. The term,
"
"land disturbance activity",does not mean the following:
(1)
Minor land disturbance activities such as home gardens and an individual's home landscaping,
repairs, and maintenance work.
(2)
Construction, installation, and maintenance of electric, telephone, and cable television utility
lines or individual service connections to these utilities, except where a minimum of 10,000
square feet of land disturbance can be anticipated.
(3)
Tilling,planting, or harvesting of agricultural, horticultural, or silvicultural crops.
(4)
Installation of fence, sign, telephone, and electric poles and other kinds of posts or poles.
(5)
Emergency work to protect life, limb, or property and emergency repairs. However, if the land
disturbing activity would have required an approved erosion and sediment control plan except
2
for the emergency, the land area disturbed shall be shaped and stabilized in accordance with
the requirement of the local plan-approving authority or the district when applicable.
and mean
Ramsey County Erosion and Sediment Control Handbookhandbook
the most recent edition of the handbook which contains the erosion and sediment
control practice specifications and planning procedures to control soil erosion and
sedimentation. The Ramsey County Erosion and Sediment Control Handbook shall
be adopted by the Ramsey Soil and Water Conservation District.
MPCAmeans the Minnesota Pollution Control Agency.
MPCA’s Construction Stormwater Permitmeans the most current adopted Minnesota Pollution
Control Agency general permit to Discharge Stormwater Associated with Construction Activity.
MSMS means the most current version of the Maplewood Stormwater Management Standards.
Sedimentmeans solid mineral or organic material that, in suspension, is being transported or has
been moved from its original site by air, water, gravity, or ice and has been deposited at another location.
Sedimentationmeans the process or action of depositing sediment that is determined to have been
caused by erosion.
(Code 1982, 11.5-3)
Cross reference
Definitions generally, 1-2.
[
-
Sec. 18-144. Erosion and sediment control plan.
(a)
Required.Every applicant for a building permit, a subdivision approval,grading permit, or a permit to
city
allow land disturbing activities must submit an erosion and sediment control plan to the
engineer.
City.No building permit, subdivision approval, grading permit, or permit to allow land
disturbing activities shall be issued until approval of the erosion and sediment control plan.
(b)
addressfollowing
Criteria addressed. The erosion and sediment control plan shall meet the
criteria:
(1)
Stabilize all exposed soils
requirements of the MPCAs Construction Stormwater Permit
soil stockpiles.
and
(2)
Establish permanent vegetation.
(3)
Prevent sediment damage to adjacent properties and other designated
areas.
3
(4)
Schedule erosion and sediment control practices.
(5)
Use temporary sedimentation basins.
(6)
Engineer the construction of steep slopes.
(7)
Control stormwater leaving a site.
the MSMS.
(8)
Stabilize all waterways and outlets.
(9)
Protect storm sewers from the entrance of sediment.
(10)
When working in or crossing water bodies, take precautions to contain
sediment.
(11)
Restabilize utility construction areas as soon as possible.
(12)
Protect paved roads from sediment and mud brought in from access routes.
(13)
Dispose of temporary erosion and sedimentcontrol measures.
(14)
Maintain all temporary and permanent erosion and sediment control
practices.
(c)
include the following:
Contents of plan. The erosion and sediment control plan shall
(1)
Project description:
meet the plan requirements of the MPCA’s Construction Stormwater Permit and
nature and purpose of the land disturbing activity and the amount of grading
the
involved.
MSMS.
(2)
Phasing of construction: the nature and purpose of the land disturbing
activityand the amount of grading, utilities, and building construction.
4
(3)
Existing site conditions: existing topography, vegetation, and drainage.
(4)
Adjacent areas, neighboring streams, lakes, residential areas, roads, etc.,
which might be affected by the land disturbing activity.
(5)
Soils: soil names, mapping units, erodibility.
(6)
Critical erosion areas: areas on the site that have potential for serious
erosion problems.
(7)
Erosion and sediment control measures: methods to be used to control
erosion and sedimentation on the site, both during and after the
construction process.
(8)
Permanent stabilization: how the site will be stabilized after construction
is completed, including specifications.
(9)
Stormwater management: how storm runoff will be managed, including
methods to be used if the development will result in increased peak rates
of runoff.
(10)
Maintenance: schedule of regular inspectionsand repair of erosion and
sediment control structures.
(11)
Calculations: any that were made for the design of such items as sediment
basins, diversions, waterways, and other applicable practices.
(d)
Where, in the judgment of a registered professional engineer
Variance.
experienced in the field of erosion and sediment control, site conditions
warrant or where the practices or practice standards, as conditioned in the
handbook, will be insufficient to control erosion and sedimentation for a land
disturbance activity, the city engineer may grant a variance from the use of the
handbook on a case-by-case basis. The content of a variance shall be specific
and shall not affect other approved provisions of a plan.
5
(Code 1982, 11.5-4)
-
Sec. 18-145. Review of plan.
(a)
the city engineer
Generally.The city appoints a staff memberto review the erosion and sediment
Ramsey County Erosion
control plan. The most current version of theMPCA’s BMP Manual
Sediment Control Handbook is
andthe MSMS arethe reference for erosion and sediment
The city engineer shall review the erosion and
control practice specifications in the city.
sediment control plan within seven days of receiving the plan from the
developer.
(b)
Permitrequired
Approval process.If the city determines that the erosion and sediment control
plan meets the requirements of this article, the developerwill be instructed to proceed with the
installation of the proposed erosion and sediment control BMP’s. Once the erosion and sediment
control BMP’s are installed the applicantwill contact the city for a field inspection. If additional
BMP’s are found to be required or if thereareany adjustments to the installed BMP’s the city shall
notify the applicant. A follow up inspection will be scheduled after the requested changes are made.
Once the field inspection has been approved the city shall issue a permit, valid for a specified period
of time, that authorizes the land disturbance activity contingent on the implementation and
completion of the erosion and sediment control plan.
(c)
Denial.If the city determines that the erosion and sediment control plan does not meet the
requirements of this article, the city shall not issue a permit for the land disturbance activity. The
erosion and sediment control plan must be resubmitted for approval before the land disturbance
developer
activity begins. All land use and building permits must be suspended until the applicant
has an approved erosion and sediment control plan.
(d)
Permit suspension.If the city determines that the approved erosion and sediment control plan is not
the
being implemented according to thatschedule or the control measures are not being properly
developer
maintained, all land use and building permits must be suspended until the applicanthas
fully implemented and maintained the control measures identified in the approved erosion and
sediment control plan.
(Code 1982, 11.5-5)
-
Sec. 18-146. Modification of plan.
An approved erosion and sediment control plan may be modified on submission of an application for
.
modification to the city and subsequent approval by the city engineeror appointed staff member.In
engineer
reviewing such application, the citymay require additional reports and data.
6
(Code 1982, 11.5-6)
-
Sec. 18-147. Escrow requirement.
payer
After approval of an erosion and sediment control plan, the city shall require the applicantto
escrow a sum of money sufficient to ensure the installation, completion, and maintenance of the erosion
as set fromtime to time by the city council.
and sediment control plan and practices.The
However, the
escrow may be reduced, upon request, after phases of the project are complete. The
shall not be less than $1,000.00
escrow amount will vary depending on the size and scope of the
thepayer
project. Upon project completion, all remainingescrow shall be returned to the applicant.
(Code 1982, 11.5-7)
-
Sec. 18-148. Enforcement; penalty.
(a)
The city shall be responsible for the enforcement of this article.
(b)
deemed
Any person who fails to comply with or violates any section of this article shall be
guilty
charged withof a misdemeanor and, upon conviction, shall be subject to punishment in
accordance withsection 1-15. All land use and building permits shall be suspended until the
developer
applicanthas corrected the violation and amended the erosion and sediment control
plan for the land disturbance activity. Each day that a separate violation exists shall constitute a
separate offense.
(Code 1982, 11.5-8)
-
Secs. 18-14918-175. Reserved.
[
FOOTNOTE(S):
5
--- () ---
Cross reference—
Erosion control and soils, § 12-309; streets, sidewalks and other public places, ch.
32.(Back)
State Law reference—
Soil erosion generally, Minn. Stats. § 103F.401 et seq.; authority of city to adopt a
soil erosion ordinance, Minn. Stats. § 103F.405.(Back)
7
Attachment 2
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[7]
ARTICLE VII. STORMWATER MANAGEMENT
FOOTNOTE(S):
7
---()---
Editor's note
Ord. No. 903, 2, adopted June 14, 2010, set out provisions intended for use as
[
18-18018-183. For purposes of sequential numbering, and at the editor's discretion, these provisions
[
have been included as 18-27118-274. Sec. 18-271. Applicability.
[
Sec. 18-272. Erosion control.
Sec. 18-273. Illicit discharges.
Sec. 18-274. Regulating use of coal tar-based sealer products.
Secs. 18-275—18-300. Reserved.
-
Sec. 18-271. Applicability.
management standards
The Maplewood Stormwater Management Standards (MSMS) serves
as the guiding document for stormwater design within the City of Maplewood. The City Engineer or
apply to
designated city staffshall use engineering judgment during the design or review of storm sewer
systems to determine if the design meets the requirements and/or intent of the MSMS.
which result in one-half-acre (21,780
Allnew development and redevelopment projects
square feet) or more of or 5,000
meeting and/or exceeding the thresholds for disturbed area
square feet or more of .
and/or new impervious surfacearea, as defined by theMSMS, shall meet
the requirements forrunoff ratesand water quality treatment as set forth by theMSMS.
(1)
a)Runoff rates.Runoff rates resulting from a project subject to the standards shall not exceed the
pre-project runoff rates for the two-year, ten-year, and 100-year critical duration storm events.
(2)
A runoff volume of at least one inch, over all new
b)Water quality treatment.
impervious and redevelopment impervious portions of a project, must be
treated through
To themaximum extent practicable the requiredinfiltration volume, as
defined by the MSMS, shall be met onsite.
1)All proposed infiltration and filtration practicesshall meet the requirements of the MSMS.
1
a.
Filtration practices that are designed for partial recharge (e.g.,
bioretention basin with under drains) shall receive 70 percent credit
for the runoff volume treatment requirement of one inch.
b.
2)For projects where infiltration or filtration is not feasible, or is prohibited as described in the
stormwater management standards, the project must provide treatment
systems that remove 90 percent total suspended solids (TSS) and 60
percent total phosphorus (TP) on an annual basis
MSMS, the project mustmeet
the mitigation provision of the MSMS.
(Ord. No. 903, 2, 6-14-2010)
-
Sec. 18-272. Erosion control.
Erosion control standards apply to all land disturbance activity unless specifically exempted by the
definition of the term "land disturbance activity" in the city's erosion and sedimentation control ordinance
provided in section 18-143.
(Ord. No. 903, 2, 6-14-2010)
-
Sec. 18-273. Illicit discharges.
a)Definitions: The following words, terms and phrases, when used in this article, shall have the
meanings ascribed to them in this section, except where the context clearly indicates a different
meaning:
1)Illicit Connectionmeans any drain or conveyance, whether on the surface or subsurface,
which allows an illicit dischargeto enter the storm drain system including but not limited to
any non-stormwater discharge such as sewage, process wastewater, and wash water, and
any connections to the storm drain system from indoor drains and sinks, regardless of
whether said drain or connection had been previously allowed, permitted, or approved by an
authorized enforcement agency.
2)Illicit Discharge means any discharge to a municipal separate storm sewer system that is not
composed entirely of stormwater except discharges pursuant to a National Pollutant
Discharge Elimination System (NPDES) permit (other than the NPDES permit for discharges
from the municipal separate storm sewersystem) and discharges resulting from firefighting
activities.
3)Municipal Separate Storm Sewer System(MS4) means a stormwater conveyance or unified
stormwater conveyance system (including but not limited to roads with drainage systems,
municipal streets, catch basins, stormwater detention facilities, water quality treatment
systems, curbs, gutters, ditches, natural or man-made channels, or sidewalks) owned and
operated by the City of Maplewood and designed or used for collecting or conveying
stormwater, and that is not used for collecting or conveying sewage.
4)Non-stormwatermeans any discharge to the municipal stormsewersystem that is not
composed entirely of stormwater.
2
5)Stormwatermeans any surface flow, runoff, and drainage consisting entirely of water in the
form of natural precipitation, and resulting from such precipitation.
6)Storm SewerSystem meansany facility by which stormwateris collected and/or conveyed,
including but not limited to any roads with drainage systems, municipal streets, gutters, curbs,
inlets, piped storm drains, pumping facilities, retention and detentions basins, natural and
human made or altered drainage channels, reservoirs, water quality treatment systems, and
other drainage structures.
b)Prohibition of illicit discharges: No person shall throw, drain, or otherwise discharge, cause, or
its
allow others under theircontrol to throw, drain, or otherwise discharge into the municipal
separate storm sewer system any non-stormwater, pollutants,or waters containing any
pollutants other than stormwater. The following discharges are exempt:
(1)
1)Water line flushing performed by a government agency, other potable water sources,
landscape irrigation or lawn watering, diverted stream flows, rising groundwater,
groundwater infiltration to storm drains, uncontaminated pumped groundwater, foundation or
footing drains (not including active groundwater dewatering systems), crawl space pumps,
air conditioning condensation, springs, natural riparian habitat or wetland flows, irrigation
water, individual residential car washing, dechlorinated swimming pool discharges, street
wash water, and any other water source not containing pollutants;
(2)
2)Discharges or flows from fire fighting, and other discharges specified in writing by the city as
being necessary to protect public health and safety;
(3)
3)The prohibition provision above shall not apply to any non-stormwater discharge permitted
under an National Pollutant Discharge Elimination System (NPDES) permit or order issued
to the discharger and administered under the authority of the State and the Federal
Environmental Protection Agency, provided that the discharger is in full compliance with all
requirements of the permit, waiver, or order and other applicable laws and regulations, and
provided that written approval has been granted for any discharge to the (municipal/county)
separate storm sewer system.
(4)
4)These requirements do not replace or supersede other city ordinances, watershed district
rules or permit requirements, or state and federal rules or permits required for the project.
c)Prohibition of illicit connections: No person shall use any illicit connection to intentionally convey
non-stormwaterto a storm sewersystem. The construction, use, maintenance or continued
existence of illicit connections to astorm sewersystemis prohibited. This prohibition includes,
without limitation; illicit connectionsmade in the past, regardless of whether the connection was
permissible under the law or practices applicable or prevailing at the time of connection.
d)Inspection, monitoring, and testing:In response to areported and/or identified illicit discharge the
City shall track the illicit discharge back to its source.
1)TheCity Engineer and other duly authorized employees of the City, bearing proper
credentials and identification, shall at reasonable times be permitted to enter upon all
properties in the city utilizing proper procedures for the purpose of inspection, observation,
emergency response, measurement, sampling and testing in connection with illicit discharge
and the operation of the storm sewersystem.
3
2) The City of Maplewood shall be permitted to enter and inspect facilities subject to regulation
under this division as necessary to determine compliance with this division.
3)The City of Maplewood shall have the right to set up at any storm sewersystem devices
necessary in the opinion of the City to conduct monitoring, sampling and/or dye testing of
the facility’s stormwater dischargewithout need of securing any easement, license or permit
from the landowner.
e)Violations, penalties and remedies:It shall be unlawful to violate any provisions or fail to comply
with any of the requirements of this ordinance.
1)The City may send a letter of notice explaining to the person(s) responsible for the violation
what activities need to change and potential impacts that continuing such activities may
have.
2)The City may send a code enforcement letter to the person(s) responsible for the violation
explaining what activities need to change, the cleanup measures that need to performed by
the individual(s), a deadline for completing the cleanup work,and the penalties for failing to
meet the cleanup deadline.
3)The City may take legal action against any person(s) violating any provision of this article.
Any person(s) violating any provision of this article may be charged with a misdemeanorand
be subject to criminal penalties and restitution, if any.
4)In the event the violation constitutes an immediate danger to public health or safety, the city
is authorized to enter upon the subject property without giving prior noticeto take any and all
measures necessary to abate the violation and/or restore the property.In the event that the
City is forced to perform such abatement, the costs shall be assessed to the property.
5)The City may, without prior notice, suspend storm sewer system access to any building/site
when such suspension is necessary to stop an actual or threatened discharge which
presents or may present imminent and substantial danger to theenvironment, to the health
or welfare of persons, or to the stormsewersystem or surface waters.
6)Failure to comply with a suspension order issued in an emergency will result in any process
deemed necessary to prevent or minimize damage to the stormsewersystem or surface
waters, or to minimize danger to personsor property.
f)Remedies not exclusive:The remedies listed in this division are not exclusive of any other
remedies available under any applicable federal, state, or local law and it is within the discretion
of the City of Maplewood to seek cumulative remedies. The City of Maplewood may recover all
attorney’s fees, court costs, and clean up costs associated with enforcement of this division
including sampling and monitoring expenses.The City may recover all fees and costs by
assessing the costs tothe property.
g)Compatibility with other regulations: This ordinance is not intended to modify or repeal any other
ordinance, rule regulation, or other provision of law. The requirements of this ordinance are in
addition to the requirements of any other ordinance, rule, regulation, or other provision of law,
and where any provision of this ordinance imposes restrictions different from those imposed by
any other ordinance, rule, regulation, or other provision of law, whichever provision is more
restrictive or imposes higher protective standards for human health or the environment shall
control.
h)Severability:If any provision of this ordinance is found to be invalid for any reason by a court of
competent jurisdiction, the validity of the remaining provisions shall not be affected.
(Ord. No. 903, 2, 6-14-2010)
4
-
Sec. 18-274. Regulating use of coal tar-based sealer products.
(a)
Purpose.The city understands that lakes, rivers, streams and other bodies of water are natural
assets which enhance the environmental, recreational, cultural and economic resources and
contribute to the general health and welfare of the community. The use of sealers on asphalt
driveways is a common practice. However, scientific studies on the use of driveway sealers have
demonstrated a relationship between stormwater runoff and certain health and environmental
concerns. Regulation of sealer products within the city is needed in order to protect, restore, and
preserve the quality of its waters.
(b)
Definitions.Except as may otherwise be provided or clearly implied by context, all terms used in this
article shall be given their commonly-accepted definitions. For the purpose ofsection 18-274of this
clear
article, the following definitions shall apply unless the context clearlyindicates or requires a
different meaning:
Asphalt-based sealer.A petroleum-based sealer material that is commonly used on driveways,
parking lots, and other surfaces and which does not contain coal tar.
Coal tar.A byproduct of the process used to refine coal.
Coal tar-based sealer.A sealer material containing coal tar that has not been mixed with asphalt and
which is commonly used on driveways, parking lots and other surfaces.
PAHs (polycyclic aromatic hydrocarbons).A group of organic chemicals formed during the
. Present
incomplete burning of coal, oil, gas, or other organic substances presentin coal tar and
believed harmful to humans, fish, and other aquatic life.
(c)
Prohibitions.
(1)
No person shall apply any coal tar-based sealer to any driveway, parking lot, or other surface
within the city.
(2)
No person shall contract with any commercial sealer product applicator, residential or
commercial developer, or any other person for the application of any coal tar-based sealer to
any driveway, parking lot, or other surface within the city.
(3)
No commercial sealer product applicator, residential or commercial developer, or other similar
individual or organization shall direct any employee, independent contractor, volunteer, or other
person to apply any coal tar-based sealer to any driveway, parking lot, or other surface within
the city.
(d)
Exemption.Upon the express written approval from both the city and the MPCA, a person
conducting bona fide research on the effects of coal tar-based sealer products or PAHs on the
section 18-274
environment shall be exempt from the prohibitions provided insection 18-274
(e)
5
Asphalt-based sealcoat products.The provisions of this article shall only apply to use of coal tar-
based sealer in the city and shall not affect the use of asphalt-based sealer products within the city.
(Ord. No. 903, 2, 6-14-2010)
-
Secs. 18-27518-300. Reserved.
[
FOOTNOTE(S):
7
--- () ---
Editor's note
Ord. No. 903, 2, adopted June 14, 2010, set out provisions intended for use as
[
18-18018-183. For purposes of sequential numbering, and at the editor's discretion, these provisions
[
have been included as 18-27118-274. (Back)
[
6
Attachment 3
Chapter 40
ARTICLE II Sewers
-
DIVISION 1. GENERALLY
Sec. 40-26. -Operation of municipal sanitary sewer system as public utility.
Sec. 40-26. Operation of municipal sanitary sewer system as public utility.
Sec. 40-27. Discharges from properties.
Sec. 40-28. Right of entry.
Sec. 40-29. Causing damage to sewer system.
Sec. 40-30. Variations from requirements of article.
Sec. 40-31. Violations of article.
Secs. 40-32—40-60. Reserved.
Sec. 40-26. Operation of municipal sanitary sewer system as public utility.
The entire municipal sanitary sewer system of the city shall be operated as a public utility and
convenience from which revenues will be derived, subject to this article.
(Code 1982, 28-1)
-
Sec. 40-27. Discharges from properties.
his
No person shall discharge out of or permit to flow from anyresidence or place of business or any
other property operated or owned by such person any foul or odorous liquids, slops or substances into
street, lane
any street, lane,private ground,or public ground within the city or into any body of water,
stream or ditch, except into a sanitary sewer pursuant to this article. Violation of this ordinance may be
deemed as an illicit discharge in accordance with Sec. 18-273.
(Code 1982, 28-2)
1
-
Sec. 40-28. Right of entry.
The city engineer and other duly authorized employees of the city, bearing proper credentials and
identification, shall at reasonable times be permitted to enter upon all properties in the city utilizing proper
procedures for the purpose of inspection, observation, measurement,emergency response, sampling and
testing in connection with the operation of the municipal sanitary sewer system.
(Code 1982, 28-3)
-
Sec. 40-29. Causing damage to sewer system.
No person shall maliciously, willfully or negligently break, damage, destroy, uncover, deface or
tamper with any structure, appurtenance or equipment which is a part of the municipal sewer system.
(Code 1982, 28-4)
-
Sec. 40-30. Variations from requirements of article.
plumbing
The sewerinspector may permit variations from the strict application of any of the
he is
sections of this article if satisfied that there are special circumstances or conditions affecting the
variance
premises for which the variationis requested and that the granting of such variation will not
materially adversely affect health, safety or general welfare or public or private property. Any variation
permitted under this section must be noted on the permit.
(Code 1982, 28-5)
-
Sec. 40-31. Violations of article.
Unless expressly otherwise provided, any personfoundguilty of violating any section of this article
.
shall be guilty of a misdemeanor and, upon conviction, shall be punished in accordance withsection 1-15
and or to the extent allowed under Minnesota law and may also be required to pay any restitution for
costs associated with the violation, e.g. clean-up costs borne by the City.
(Code 1982, 28-6)
-
Secs. 40-3240-60. Reserved.
[
2
Attachment 4
Maplewood Engineering Regulations
April 9, 2010
XXXXX XX, 2015
Maplewood Stormwater Management Standards
The City of Maplewood has developed specificstormwater management standardrequirements
in this section that apply to development and redevelopment projects. These standards are
intended to help achieve the water resource goals of the City’s Surface Water Management Plan
(SWMP) and help the City maintain compliance with the National Pollutant Discharge
Elimination System (NPDES) municipal permit program.(which Maplewood holds a permit to
participate in).These standards highlight important aspects of the requirements for stormwater
quality, discharge rate and volume control, erosion control, and illicit discharge.
These standards do not replace or supersede City ordinances, watershed district regulations, state
and federal rules or permits required for the project. For a more detailed listing of requirements
see the specific policies of the City’s SWMP and the applicable City ordinances,or consult with
City staff on your specific project.
To accomplish the goals of the SWMP, it is important tothatthe City to have consistent
approaches toinevaluating proposed development and redevelopment projects. Therefore, all
hydrologic, hydraulic and water quality analysis must be prepared and submitted in a format that
will allow for a timely and efficient review by City staff.
Project designers and/or developersare encouraged to schedule and complete a pre-design
meeting with the City before any data will be accepted.is submitted for review.The purpose of
the meeting is to specifically address approvals and permits, ponddetailed designrequirements,
trunk storm drain analysis, wetland impacts, water quality treatment, erosion control and
discharge to lakes and sensitive wetland resources.
The Maplewood Stormwater Management Standards serve as the guiding document for
stormwater design within the City of Maplewood. The City Engineer or designated city staff
shall use engineering judgment during the design or review of storm sewersystems to determine
if the design meets the requirements and/or intent of the Maplewood Stormwater Management
Standards as set forth herein.
1)General
a)Erosion controlstandards apply to all land disturbance activity unless specifically
exempted by the definition of the term,“land disturbance activity””,in the City’s Erosion
and Sedimentation Control Ordinance.
b)The City’s water quality treatment and rate control requirements apply to projects which
result inone-half acreor twenty-one thousand, seven hundred eighty (21,780) square feet
1
or more of disturbed area or five thousand (5,000)square feet or more of new impervious
surface, and.
c)Projects conducting mill and overlay, full depth mill,or other surface pavement
treatments,(where aggregate base isleft undisturbed,not excavated),on existing
imperviousareas are exempt from the City’s water quality treatment and rate control
requirements. However, requirements must be met if the project impactsrequires
excavation and/or removal ofthe base and/or sub-base materials for 21,780 square feet
(one-half acre)or more of disturbed area.
d)Projectsinthe Floodplain Overlay District or Shoreland Overlay District may have
additional requirements whichare defined in the City’s Floodplain and Shoreland
Ordinancesand/or the Watershed District regulations.
e)Any work within a wetland, surface water, or Federal Emergency Management Agency
(FEMA) designated floodplain may require permits to be obtained from, but not limited
to,the City, watershed districtWatershed District, Department of Natural Resources
(DNR) and/orthe U.S. ArmyCorps of Engineers. All applicable permits for the specific
project must be obtained prior to commencing land disturbance, construction, grading,
clearing, or filling activities.
f)The owner shall submit the information listed in Section 8 (Stormwater Plan Submittals)
of these Standards to the City for review.
2)Water Quality Treatment.
a)Infiltration/Volume Control Requirement
1)For allnew imperviousportionsof a projector all impervious portions of a
redevelopment project, a runoff volume of one (1)inch.1inchesmust be treated
throughinfiltrationpractices.
2)For all redevelopment impervious portions of a project, a runoff volume of 1 inch
must be treated throughinfiltration practices.
3)2)Filtration practices that are designed for partial recharge (e.g., bioretention basin
with under drains) shall receive seventyfifty fivepercent (7055%)credit for
infiltration/volume control.Trees and shrubs are encouraged to be incorporated into
filtration practice designs.
3)Filtration practices that incorporate iron-enhanced sand used as a filtration media
shall receive eighty percent (80%) credit for infiltration/volume control.
(1)Iron-enhanced media shall include a minimum of 5% of iron filings by weight and
shall be uniformly blended with filtration media.
b)Pollutant Removal Requirements. For projects that have met the infiltration/volume
control requirements above, the pollutant removal requirements are considered to be met.
For projects where infiltration or filtration is not feasible or is prohibited (see Item 5.a.),
the following pollutant removal standards (based on a standard Nationwide Urban Runoff
2
Program, NURP, particle size distribution) apply prior to reaching a downstream
receiving water:
1)ForForredevelopment portions of a site ornew development portions of a site,
provide treatment to remove ninety percent (90%) total suspended solids (TSS) and
sixty percent (60%)total phosphorus (TP) as modeled on an annual basis.
2)For redevelopment portions of a site, provide treatment to remove 90% TSS and 60%
TP as modeled on an annual basis.
c)Mitigation Provisions. To the maximum extent practicable post construction
management for water quality treatmentshall be fully met onsite. For projects where the
conditions for post-construction stormwater management for water quality treatment
cannot be cost effectively met on site, as determined by the City and described by Item
5.a. and Item 5.b.,the following mitigation requirements shall be met:
1)Mitigation project areas are selected in the following order of preference:
(1)Locations that yield benefits to the same receiving water that receives runoff from
the original construction activity.
(2)Locations within the same Department of Natural Resource (DNR) catchment
area as the original construction activity.
(3)Locations in the next adjacent DNR catchment area up-stream.
(4)Locationsanywhere within the permittee’s jurisdiction.
2)Approval of mitigation projects, for all that are required to meet the post construction
management for water quality treatment with a proposed disturbed area between 0.5
acre and 1 acre, shall be coordinated with the City.
3)Approval of mitigation projects, for all that are required to meet the post construction
management for water quality treatment with a proposed disturbed area of1 acre or
greater, shall be coordinated with the City and the appropriate watershed district.
4)Mitigation projects must involve the creation of new permanent stormwater Best
Management Practices (BMPs) or the retrofit of existing permanent stormwater
BMPs, or the use of a properly designed regional permanent stormwater BMP.
5)Routine required maintenance of existing permanent stormwater BMPs cannot be
used to meet mitigation requirements.
6)Mitigation projects shall be completed within 24 months after the start of the original
construction activity.
7)The City shall determine, and document, who is responsible for long-term
maintenance on all City approved mitigation projects.
8)As a last alternative, on projects that are required tomeet the post construction
managementfor water quality treatmentwith a proposed disturbed area between 0.5
acres and 1acre, the applicant shall pay into the City’s Environmental Utility Fund
3
(EUF) to cover the cost of implementing an equivalent mitigation project in
accordance with the above requirements.
(1)The required amount to contribute to the EUF shall determined based on the size
and scope of each project.
(2)Money contributed to the EUF,to offset the post construction management of
water quality treatment that was not achieved on the permitted development, shall
be utilized by the City to construct public stormwater projectsthat address water
quality.
9)As a last alternative, on projects that are required to meet the post construction
management for water quality treatment with a proposed disturbed area of 1acre or
greater, the applicant shall coordinate with the City and the appropriate watershed
district to pay into a stormwater impact fundmanaged by the watershed district.
3)Rate Control.
a)Discharge rates leaving the site must not exceed the current rates for the 2, 10 and
100-year, critical duration (24-hour)storm events, using aType IIstorm distribution and
antecedent moisture conditions 2 (AMC-2).)and the National Weather Service (NOAA)
Atlas 14 rainfall depths and distributions.
b)On-site rate controls may not be needed if downstream (regional) facilities can be shown
to adequately detain/retain the runoff to existing conditions. In this case, the developer or
design engineer shall submit a technical evaluation completed by a qualified engineer
which must be reviewedand approved by the City Engineeror their designee.
c)Where a flow rate variance involves inter-community issues or significant water bodies,
the regulatory jurisdiction(e.g. watershed district, DNR, adjacent city) shall have a
review role. Any variancesto the City of Maplewood’s Standardsshall be reflected in
subsequent plan submittals.
4)Design Computations.
a)All hydrologic data shall be completed using NRCS methodology; i.e. HydroCAD or
TR20/TR55, XP-SWMM or a comparable, City approved,method. Hydraulic
calculations will be accepted in the rational method format or in commonly used software
packages such as FHWA HY-8, Eagle Point or XP-SWMM or a compatiblecomparable,
City approved method. These computations shall be submitted to the City upon request.
4
b)Rainfall amounts for hydrologic analysis shall be based on Hershfield, D.M., 1961,
Rainfall Frequency Atlas of the United States for Duration of 30 Minutes to 24 Hours and
Return Periods from 1 to 100 Years. Technical Publication No. 40 (TP-40).Atlas 14 data.
Maplewood analyses shall use the values in the following table.
Rainfall FrequencyRainfall (Inches)
2-Year 24-Hour2.9
10-Year 24-Hour4.3
100-Year 24-Hour6.07.5
c)For projects that do not meet the infiltration/volume control requirement, design
engineers and developers shall determine the pollutant removal efficiency of the best
management practices (BMPs)incorporated into the site plan using the available industry
standard models including P8 (and using a standard NURP particle size distribution for
the analysis) or a comparable model approved by the City. As an alternative to preparing
a site-specific model, the development may provide a treatment volume (dead storage) of
not less than two and one-half (2.5)inches multiplied by the runoff coefficient calculated
over the contributing drainage area to the pond. For example, a one (1)acre impervious
site with a runoff coefficient of 0.90 that drains to a common treatment pond would be
required to provide a dead storage volume of 0.19 acre-feet or eight thousand two
hundred (8,200)cubic feet.The Natural Resources Conservation Service Method may
also be used upon City approval.), Win-SLAMM, MIDSor a comparable model
approved by the City.
d)The volume reduction (in cubic feet) provided by surface infiltration practices shall be
computed using the Ramsey-Washington Metro Watershed District’s (RWMWD)
Volume Control Worksheet (available online at www.rwmwd.org). An alternative
computation method may be used if the method considers the same factors as the
RWMWD worksheet and provided the method is approved by the City Engineer prior to
the project information being submittedto the City for review.Volume reduction (in
cubic feet) calculations shall be submitted to the City for reviewforall surface infiltration
practices.
e)Local storm sewer systems shall be designed for the 10-year storm event. The Rational
Method shall be the preferred methodology for the design of localsystems. Culvert
crossings or storm systems in County or State right-of-way may have a design frequency
which differs from the City’s 10-year design storm. The designer shall contact each
agency/unit of government to determine the appropriate design frequency for
hydrologically-connected systems.
f)For culvert outlet velocities less than or equal to four (4)feet per second (fps), check
shear stress to determine if vegetation or riprap will be adequate. If vegetation is used,
temporary erosion control during and immediately followingconstruction shall be used
until vegetation becomes established. For velocities greater than four (4)fps, energy
dissipaters shall be designed in accordance with Mn/DOT Design Criteria.
g)High water elevationsforlandlocked areas(basins where no outlet exists)shall be
established by first estimating the normal or initial water surface elevation at the
5
beginning of a rainfall or runoff event using a documented water budget,evidence of
mottled soil, and/or an established ordinary high water level.The high water level
analysis shallbe based on runoff volume resulting from a 100-year/10-day runoff
(7.2event(10.0inches and saturated or frozen soil conditions [CN=100]) and/or the
runoff resulting from a 100-year back-to-back event (6.07.5inches followed by 6.07.5
inches). The high water elevation shall be the higher of these two conditions.
h)TheFor all new development and redevelopment projects thelowest floor elevation (LFE)
of all buildings shall be set:
1)Utilizing the latest Atlas 14rainfall frequency data.
1)2)At least two (2) feet above the 100-year high water elevation and at least one (1)
foot above a designated emergency overflow.
2)3)For landlocked basins, at least five (5) feetabove the higher of the elevations
determined in Part 4.g.
5)Volume Control/Infiltration Practices Design Criteria.
a)Infiltration systems are prohibited:
1)Where the bottom of the infiltration basin is less than three (3)feet to bedrock or the
seasonally high water table;
2)LowIn areas of lowpermeability soils (i.e., Hydrologic Soil Group D soils) or where
a confining layer exists below the proposed basin;
3)Within fifty (50)feet of apublic or private “water supply well” as defined by(Minn.
Rules, Chapter 4725);
4)Potential stormwater hotspotsAreas where soil has been determined to not meet
MPCA unrestricted use criteriaor contaminated soils;
5)4)contamination has been identified in groundwater at levels that exceed Minnesota
Department of Health (MDH) drinkingwater standards.Within ten (10)feet of a
property line or building foundation;and
6)5)Within thirty-five(35)feet of a septic system tank or drain field.
6)Where industrial facilities are not authorized to infiltrate industrial stormwater under
an NPDES/SDSIndustrial Stormwater Permit issued by the MPCA,and:
7)Where vehicle fueling and maintenance occur.
b)Restrict the use of infiltration techniques, without higher engineering review, sufficient to
provide a functioning treatmentsystem and prevent adverse impacts to groundwater,
when the infiltration device will be constructed in areas:
1)Within 1,000 feet up-gradient, or 100 feet down-gradient of active karst features, and;
2)Where soil infiltration rates are more than 8.3 inches per hour.
3)Within a Drinking Water Supply Management Area (DWSMA) as defined in Minn.
R. 4720.5100, subp. 13.
6
b)c)Infiltration practices must be designed to draw down to the bottom elevation of
the practice within forty-eight (48)hours. Theponding depth shall be based on the soil
infiltration rate determined from site-specific soils-investigation data taken from the
location of proposed infiltration practices on the site(e.g., double ring infiltrometer test).
The maximum ponding depth, regardless of infiltration rate shall be two (2)feetunless
otherwise approved by the City Engineer.or their designee.The soils-investigation
requirement may be waived for residential property practices where the maximum
ponding depth is one (1) foot or less. The following infiltration rates shall be used for the
most restrictive underlying soil unless otherwise supportedby anin-situinfiltration test:
ASTM Unified
Soil
RateSoil TexturesSoil Class
Group
Symbols
1.63 in/hrGW, GP
Gravel, sand, sandy gravel, silty
A
gravel, loamy sand, sandy loam
0.80 in/hrGM, SW, SP
0.60 in/hrSM
BLoam, silt loam
0.30 in/hrML, OL
Sandy clay loam
C0.20 in/hrGC, SC
Clay loam, silty clay loam, sandy CL, CH, OH,
D0.00 in/hr
clay, silty clay, or clayMH
Source: Minnesota Stormwater Manual, November 2005.
7
Source: Minnesota Stormwater Manual, January 2014.
c)d)Infiltration practices shall have provisions for pretreatment of the runoff.
Examples of pretreatment include: a mowed grass strip between a curb-cut and a small
rain garden, a sump manhole or manufactured sediment trap prior to an infiltration basin,
and a sediment forebay as the first cell of a two-cell treatment system. Where the
infiltration system captures only clean runoff (e.g., from a rooftop) pretreatment may not
be required.at the discretion of the City Engineer or their designee.
d)e)The design shall incorporate a diversion or other method to keep construction site
sediment from entering the infiltration system prior to final stabilization of the entire
contributing drainage area.
e)f)The design shall incorporate provisions that will prohibit construction equipment from
compacting the soils where infiltration practices are proposed.
f)g)A plan for maintenance of the system must be submitted that identifies the maintenance
activities and frequency of activities for each infiltration practice on the site.A signed
maintenance agreement will be required by the City.The signed maintenanceagreement
shall:
1)Identify planned maintenance activities and frequency of activities for each BMP.
8
2)Permit the City of Maplewood andanyappropriate watershed district access to the
site to conduct inspections of identified BMPs, perform necessary maintenance, and
assess costs for the necessary maintenance when the Cityor watershed district
determines that the owner has not conducted the necessary maintenanceafter being
notified in accordance with the requirements of the signed maintenance agreement.
3)Include languageinthe maintenance agreementthat states the signed maintenance
agreement can be recorded against the property and is considered a covenant that runs
with the land until modified by a mutual agreement.
4)If there are proposed changes to the site that will cause a decrease in the effectiveness
of the BMPs then additional BMPsmay be required,along with a new maintenance
agreement to reflect and cover the proposed site changes.
6)Pond and Additional Infiltration System Design Criteria. Newly constructed or
expanded/modified ponds and basins shall be designed and constructed to meet the
following:
a)All ponds or basins shall:
1)Have a 3:1 maximum slope (above the normal water level [NWL]and below the 10:1
bench, if a wet pond);
2)Maximize the separation between inlet and outlet points to prevent short-circuiting of
storm flows;
3)Have an emergency overflow spillway identified and designed to convey storm flows
from events greater than the 100-year event; and
4)Be made accessible for maintenance and not be entirely surrounded by steep slopes or
retaining walls which limit the type of equipment that can be used for maintenance.
Vehicle access lane(s) of at least ten (10)feet shall be provided, at a slope less than
fifteen percent (15%)from the access point on the street or parking area to the pond,
to accommodate maintenance vehicles. Maintenance agreements will be required
when the pond is not located on City property.
b)All wet ponds shall:
1)Have an aquatic bench having a 10:1 (H:V) slope for the first ten (10)feet from the
NWL into the basin;
2)Have inlets be placed at or below the NWL;
3)Have a skimming device designed to remove oils and floatable materials up to a five
(5) year frequency event. The skimmer shall be set a minimum of twelve (12)inches
below the normal surface water elevation and shall control the discharge velocity to
0.5feet per second.
4)Have an average four (4)feet of permanent pool depth (dead storage depth). This
constraint may not be feasible for small ponds (less than about three [3]acre-feet in
volume or less). In such cases, depths of three to four (3-4)feet maybe used. To
prevent development of thermal stratification, loss of oxygen, and nutrient recycling
9
from bottom sediments, the maximum depth of the permanent pool should be less
than or equal to ten (10)feet.
7)Erosion and Sediment Control.
a)The City’s Erosionand SedimentControl Ordinance shall be followed for all projects,
including those not regulated under the NPDES construction permit.
b)Prior to the start of any excavationor land disturbing activity forofthe site, the owner or
contractor must have in place a functional andapproved methodof erosion and sediment
control. The contractormust have receivedreceiveauthorization from the City prior to
commencing construction activitiesregarding their proposed methodsof erosion and
sediment control.
c)Development projects subject to the NPDES Construction Permit shallmeet the
requirements of the NPDES permit program, including the requirement to prepare and
follow a storm waterstormwaterpollution prevention plan (SWPPP). The owner shall
submit proof of receipt and/orapproval by Minnesota Pollution Control Agency and/or
watershed district of the permit application prior to commencing constructionif these
permits are requiredfor the project. A copy of theSWPPP prepared in accordance with
theNPDES permit requirements, shall be submitted to the City if requestedwithin 48
hours of a requestby the CityEngineer.
d)The erosion and sediment control plan shall meet the requirements of the
Storm Water
MPCA’s Construction Stormwater Permit and address the following criteria:
1)Stabilize all exposed soils and soil stockpiles.
2)Establish permanent vegetation.
3)Prevent sediment damage to adjacent properties and other designated areas.
4)Schedule erosion and sediment control practices.
5)Use temporary sedimentation basins.
6)The construction design of steep slopes shall be performed by a licensed Professional
Engineer.
7)Control the stormwater leaving a site including any water generated from dewatering
activities.
8)Stabilize all waterways and outlets.
9)Protect storm sewers from the entrance of sediment.
10)When working in or crossing water bodies, take precautions to contain sediment.
11)Restabilize utility construction areas as soon as possible.
12)Protect paved roads from sediment and mud brought in from access routes.
13)Dispose of temporary erosion and sediment control measures(e.g. silt fence,
construction entrance material, and inlet protection).
14)Maintainall temporary and permanent erosion and sediment control practices.
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e)The erosion and sediment control plan shall meet the requirements of the MPCA’s
Construction Stormwater Permit and include the following information:
1)Project description: the nature and purpose of the land disturbing activity and the
amount of gradinginvolved(total volume of material moved).
2)Phasing of construction: the nature and purpose of the land disturbing activity and the
amount of grading, utilities, and building construction.
3)Existing site conditions: existing topography, vegetation, and drainage.
4)Identification of adjacent areas, neighboring streams, lakes, residential areas, roads,
etc., which might be affected by the land disturbing activity.
5)Soils: soil names, mapping units, erodibilitypresent on-site that will be disturbed.
6)Critical erosion areas: areas on the site that have potential for serious erosion
problems.
7)BMPs to minimize erosion, discharge of sediment, and other p0llutants: methods to
be used to control erosion, discharge of sediment, and other pollutants on the site,
both during and after the construction process.
8)Permanent stabilization: how the site will be stabilized after construction is
completed, including specifications.
9)Stormwater management: how storm water runoff will be managed.
10)BMP maintenance: schedule of regular inspections and repair of erosion and sediment
control structures.
11)Calculations: any that were made for the design of such items as sediment basins,
diversions, waterways, and other applicable practices.
12)BMPs for dewatering activities: methods to be used to filter waters if dewatering
activities are planned.
13)Site inspections and records of rainfall events: inspect the entire constructionsiteas
described by the MPCA’s Constructions Stormwater Permit.
14)Management of solid and hazardous wastes on each project site.
15)Temporary sedimentation basins: show locations, maintenance, and removal for all
temporary sedimentationbasins that are proposed tobe utilized.
8)StormwaterPlan Submittals.
a)Property lines and delineation of lands under ownership of the project proposer.
b)Delineation of the subwatersheds contributing runoff from off-site, and proposed and
existing subwatersheds on-site.
c)Location, alignment and elevation of proposed and existing stormwater facilities.
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d)Delineation of existing on-site wetlands, shoreland and/or floodplain areas. Removal or
disturbance of streambank and shoreland vegetation should be avoided. The plan shall
address how unavoidable disturbances to this vegetation will be mitigatedper the City’s
ordinances.
e)Existing and proposed inlet and outlet elevations
f)The 10-year and 100-year high water elevations on-site. For landlocked basins, the higher
of the elevations determined in Part 4.g. of these standards shall also be identified.
g)The lowest floor elevation and low opening elevation of all buildings and structures.
h)Existing and proposed site contour elevations related to NGVD, 1929 datum.North
American Vertical Datum of 1988(NAVD88).
i)Construction plans and specifications of all proposed stormwater management facilities.
j)Stormwater runoff volume and rate analyses for existing and proposed conditions.
k)All hydrologic and hydraulic computations completed to design the proposed stormwater
quality management facilities.Computations shall include a summary of existing and
proposed impervious areas.
l)All pollutant removal computations for practices not meeting the volume
control/infiltration requirement.
m)Provision of outlots or easements for maintenance access to detention basins, retention
basins, constructed wetlands,and/orother stormwater management facilities.
n)Maintenance agreement between developer and City which addresses sweeping, pond
inspection, sediment removal and disposal, etc.
o)Inlets to detention basins, wetlands, etc., shown at or below the outlet elevation.
p)Identification of receiving water bodies (lakes, streams, wetlands, etc).
q)Identification of existing and abandoned wells, and septic tanks on the development site.
r)Documentation indicating conformance with these standards.
9)Prohibition of Illicit Discharges. No person(s)shall throw, drain, or otherwise discharge,
cause, or allow others under itstheircontrol to throw, drain, or otherwise discharge into the
municipal separate storm sewer system any pollutants or waters containing any pollutants
other than stormwater, i.e.,chemically treatedswimming pool water which contains
pollutants not found in stormwater. The following discharges are exempt from the
prohibition provision above:
a)Water line flushing performed by a government agency, other potable water sources,
landscape irrigation or lawn watering, diverted stream flows, rising ground water, ground
water infiltration to storm drains, uncontaminated pumped ground water, foundation or
footing drains (not including active groundwater dewatering systems), crawl space
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pumps, air conditioning condensation, springs, natural riparian habitat or wetland flows,
and any other water source not containing pollutants;
b)Discharges or flows from fire fighting, and other discharges specified in writing by the
Cityas being necessary to protect public health and safety;
c)The prohibition provision above shall not apply to any non-stormwater discharge
permitted under an NPDES permit or order issued to the discharger and administered
under the authority of the State and the Federal Environmental Protection Agency,
provided that the discharger is in full compliance with all requirements of the permit,
waiver, or order and other applicable laws and regulations, and provided that written
approval has been granted for any discharge to the (municipal/county) separate storm
sewer system.
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