HomeMy WebLinkAbout2007 06-11 EDAP EDA MEETING
City of Brooklyn Center
June 11, 2007 AGENDA
1. Call to Order
—The EDA requests that attendees turn off cell phones and pagers during the meeting. A
copy of the full City Council packet, including EDA (Economic Development Authority), is
available to the public. The packet ring binder is located at the front of the Council
Chambers by the Secretary.
2. Roll Call
3. Approval of Agenda and Consent Agenda
—The following items are considered to be routine by the Economic Development Authority
(EDA) and will be enacted by one motion. There will be no separate discussion of these
items unless a Commissioner so requests, in which event the item will be removed from the
consent agenda and considered at the end of Commission Consideration Items.
a. Approval of Minutes
1. May 14, 2007 Regular Session
4. Commission Consideration Items
a. Resolution Accepting a Feasibility Report and Authorizing Development of Plans
and Specifications, Improvement Project No. 2007-15, TIF District 3 Regional Water
Quality Treatment Improvements
•Requested Commission Action:
Motion to adopt resolution.
5. Adjournment
f
F
T
J
y :�ro
,t r s.
J
z
c t'
t t A t.
t s
N
s
L
t 1
I
I
y
z
J
n L
f
z
f
A
'u.
L
G
r'
F i
h
X�"
'I F .Z
i
1
P
S,:.
L 4
F(
j
t
/i
f
Y:
N�� `�l
I: ti 4 4 r�-`
�e l :�l
l
X R
f:: r W
t
n.
f
.=i f
i i�
k �j`3 j
X 7
r!��� �i������ y�� w����� ������wR^' •+�������'�..F '���Y7� ���'iRI f
Y sJ
J
{i
r
,5 *„'f '.:F
Q I
k
I
l- t'{
4 "�+.y X i Y cl�
i
y
F
k
t
:€59
j
s
l f
z
u
-r
j
y .v,' L S
i F
�l
5
Y
Y' 'l ri f
r:
4
j� .F.
v
y 5
C^
w: i ri£
X
S
A
f F
J
4
Y
'z t�'
2,
F
�.Z
r
.y t
r
t
a
t
s
j
t
s
r
a
�-.t
f
._e
k
1
F 1
m
I
:i a.:
s
N r
s
3':
v
h i
..ri Y
j:
z y
.....'�.o
l
MINUTES OF THE PROCEEDINGS OF THE
ECONOMIC DEVELOPMENT AUTHORITY
OF THE CITY OF BROOKLYN CENTER
IN THE COUNTY OF HENNEPIN AND THE
STATE OF MINNESOTA
REGULAR SESSION
MAY 14, 2007
CITY HALL COUNCIL CHAMBERS
l. CALL TO ORDER
The Brooklyn Center Economic Development Authority (EDA) met in Regular Session called to
order by President Tim Willson at 9:08 p.m.
2. ROLL CALL
President Tim Willson and Commissioners Kay Lasman, Mary O'Connor, Dan Ryan, and Mark
Yelich. Also present were Executive Director/City Manager Curt Boganey, City Attorney
Charlie LeFevere, Public Works Director/City Engineer Todd Blomstrom, Planning and Zoning
Specialist Ron Warren, and Deputy City Clerk Camille Worley.
3. APPROVAL OF AGENDA AND CONSENT AGENDA
Commissioner Lasman moved and Commissioner Ryan seconded approval of the Agenda and
Consent Agenda, and the following item was approved:
3a. APPROVAL OF MINUTES
1. April 23, 2007 Regular Session
Motion passed unanimously.
4. COMMISSION CONSIDERATION ITEMS
4a. RESOLUTION NO. 2007-08 TRANSFERRING $230,000 INTO THE EARLE
BROWN HERITAGE CENTER CAPITAL FUND
Executive Director/City Manager Curt Boganey introduced the item and stated the purpose for
the proposed resolution.
Commissioner Lasman moved and Commissioner Ryan seconded adoption of RESOLUTION
NO. 2007-08 Transferring $230,000 into the Earle Brown Heritage Center Capital Fund.
Motion passed unanimously.
OS/14/07 -1- DRAFT
5. ADJOURNMENT
Commissioner Lasman moved and Commissioner Ryan seconded adjournment of the Economic
Development Authority meeting at 9:10 p.m.
Motion passed unanimously.
OS/14/07 -2- DRAFT
f
t
f
Y h!�
r` l
b YJ l
t
J
S E
f
4
t.s
f t
r
.i; ..2 s
r e S
3
S b
d
.r
T
:..v
f.
l y
`�X
l
j
Y
3'X
F
f
i
F
j
y
�5�
S
ti
v
....n..:
a .i
r t
:x
h f
v
��i�r x z
�i+. �I��
r
Y
j
G
�v
2
;-i�
i
e
J
i S
S YS
a.�:
T
y
z.
(4
�S
S �G"�:
3
F q-?
r
4 i,. '��3�
5
.'I
t:, 4
5
Y
F
3 F d
x F
J
E f
x
E
d
z t
i
z
z a
t s�
w
a
:s
y
s
x
y a
s
a
4
5 t
F.
7
t.
COUNCIL ITEM MEMORANDUM
TO: Curt Boganey, City Manager
FROM: Todd Blomstrom, Director of Public Works ��Q$
DATE: June 6, 2007
SUBJECT: Resolution Accepting a Feasibility Report and Authorizing Development
of Plans and Specifications, Improvement Project No. 2007-15, TIF
District 3 Regional Water Quality Treatment Improvements
Recommendation:
Public Works staff recommends that the Brooklyn Center City Council approve the
attached resolution accepting the feasibility report. and authorizing development of plans
and specifications for the TIF District 3 Regional Water Quality Improvement Project.
Project Background:
On March l2, 2007, the City Council established a potential water quality treatment
project near the intersection of 66�' Avenue and Highway 252. This City �ouncil action
also ordered the preparation of a feasibility report for the project. The proposed project
consists a regional underground trea.tment structure to remove sediment and pollutants
from runoff generated within the 490 acre drainage area tributary to the storm sewer main
along Freeway Boulevard. The existing trunk stoixn sewer currently conveys untreated
storm water runoff directly to the Mississippi River.
WSB Associatas has completed a feasibility report for the project. A copy of the
report is attached to this memorandum. The report recommends the installation of a
central underground treatment device located on the Rega1 Theater site that would divert
a majority of the runoff volume through a treatment system to remove trash, litter,
sediment and pollutants prior to discharging into the river. The report includes a figure
depicting the approxirnate location and drainage area for the proposed improvements.
Project Bene�it:
The Ci is currentl re uired to im lement storm water re latory mandates for new
Y P
tY q
development and redevelopment sites. Developers are often required to incorporate
storm water onds and/or other facilities into develo ment ro'ects. These ponds and
p P P J
other devices typically consume valuable development land and require perpetual
maintenance by property owners ar City staff.
The proposed water quality treatment improvements would provide a benefit to
properties within the drainage area, including several commercial properties locatecl
within TIF District No. 3. Although the improvements will not completely eliminate the
Council Resolution for TIFDistrict No. 3 Water Quality Treatment Improvements
City ofBrooklyn Center
need for on-site storm water facilities, the xegional treatment structure would reduce the
amount of land area that would normally be consumed for pond construction and the
numerous maintenance challenges associated with smaller privately and publicly owned
treatment facilities located throughout the watershed.
Design anc� Acquisition Costs:
Construction of the proposed project would require acquisition of perpetual and
temporary easements from the owner of the Regal Theater site. The Regal site owner
appears to be supportive of the project and has verbally agreed to sell the easements for
$18,735.59. The City assessor has confirmed that this is a reasonable purchase price for
the proposed easements. If the Council authorizes the project to proceed with final
design, staff will request that the City Attorney prepare the easement documents. The
easement purchase would then be presented to the City Council as a separate action at the
time that the City Council considers the construction bids.
The action requested of the City Council at tivs time is to accept the feasibility study and
authorize the development of plans and specifications for the project. A final engineer's
cost estimate and design details will be presented to the City Council for consideration to
determine if the Council wishes to proceed with bidding the project. Staff recommends
that the City engage WSB Associates to complete the plans and specifications for the
project. WSB has provided a proposal with a cost not-to-exceed of $20,000 to complete
this specialized structural and hydraulic design work.
Budget Issues:
The feasibility study provides a construction cost estimate for the project. The attached
resolution provides a total project cost estimate. The proposed funding source for the
project is tax increment revenues generated by Tax Increment Financing (TIF) District
No. 3.
Council Resolution for TIF District No. 3 Water Quality Treatment Improvements
City ofBrooklyn Center
t Member introduced the following resolution and moved its
adoption:
RESOLUTION NO.
RESOLUTION ACCEPTING ENGINEER'S FEASIBILITY REPORT AND
AUTHORIZING DEVELOPMENT 4F PLANS AND SPECIFICATIONS,
IlVIPROVEMENT PRO7ECT NO. 2007-15, TIF DISTRICT 3 REGIONAL
WATER QUALITY TREATMENT IMPROVEMENTS
WHEREAS, the Brooklyn Center City Council, by Resolution No. 2007-45 directed
the preparation of a proj ect feasibility report for the proposed construction of a regiona.l water quality
treatment facility near the intersection of State Highway 252 and 66�' Avenue North, Improvement
Project No. 2007-15; and
WHEREAS, under the direction of the City Engineer, WSB Associates has
prepared said report and recommends that the proposed improvements be considered; and
WHEREAS, the City Council has reviewed said report and desires to begin the
process of preparing plans and specifications for said improvement project.
NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of
Brooklyn Center, Minnesota, that:
L The Feasibility Report for Improvement Project No. 2007-15, TIF District 3
Regional Water Quality Treatment Improvements is received and accepted.
2. The City Manager is hereby authorized to enter into a professional services
agreement with WSB Associates in the amount not to exceed $20,000 for
prepazation ofplans and specifications for Improvement Project No. 2007-15.
3. The�preliminary estimate of the total project cost for Improvement Project Na
2007-15 is provided below. The revenue for funding the preparation ofplans and
specifications shall be derived &om t� increment revenues generated by Tax
Increment Financing (TIF) District No. 3.
Construction Contract $750,000.00
Engineering, Legal, Administration 37,500.00
Land Acquisition 18,800.00
Construction Testing and Inspection 8,500.00
Peimits and Approvals 1.500.00
Total Preliminary Project Cost Estimate $816,300.00
i!
RESOLUTION NO.
June 11, 2007
Date Mayor
ATTEST:
Ci Clerk
tY
The motion for the adoption of the foregoing resolution was duly seconded by member
and upon vote being taken thereon, the following voted in favor thereof:
and the following voted against the same:
whereupon said resolution was declared duly passed and adopted.
I
i
i
I
i
i
I
June 6, 2007
Re ional Storm�ater Treatment for
g
TIF i
D strlct 3
Prepared for:
Cify of Brooklyn Center
A p+sot piac� eo ato►R A Y►'eat Plaerto stay.
s
WSB Project No. 1143-OS
I
I
I
I
Prepared by:
i
�,::.:,..k w.SB
701 Xenia Avenue South, Suite 300
Associates lnc.
Minneapolis, MN 55416 763-541-480U
I
REGIONAL STORMWATER TREATMENT
FEASIBILITYREPORT
FOR
TIF DIST'RICT 3
PREPARED FOR THE
CITY OF BR04gLYN CENTER, M�NNESOT'A
June 6, 2007
Prepared by
WSB c� Associates, Inc.
701 Xenia Avenue South
Suite 300
Minneapolis, MN 55416
(763) 541-4800
(763} 541-1700 (faz)
I I
I Associares, lnc. Infrastructure 1 Engineering 1 Planning 1 Construction 701 Xenia Avenue South
Suite 300
Minneapolis, MN 55416
Te1:163-541-4800
Fax:763-541-1700
June 6, 2007
om PE
Nir. Todd Blomstr
Director of Public Works/City Engineer
City of Brooklyn Center
6301 Shingle Creek Pazkway
Brooklyn Center, MN 55430
Re: Regional Stormwater Treatment Feasibility Report
TIF District 3
WSB Project No. 1143-05
Dear Mr. Blomstrom:
We are pleased to submit to you the attached Regional Stormwater Treatment Feasibility Report for
'TIF District 3. This report takes into consideration the proposed plans for development and
redevelopment in T'IF District 3 and other areas draining ta the 65�' Avenue storm water system.
This report also demonstrates the improvements are feasible, cost effective, and necessary to
pmvide stormwater treatment for the region, and provides a recommended option for yow
consideration.
We would be happy to discuss this report with you at your convenience. Please don't hesitate to
contact me at 'i63 287-7182 if ou have an uestions.
Y YQ
Sincerely,
WSB Associates, Inc.
Todd E. Hubmer, PE
Project Manager
Enclosure
Minneapolis 1 St Cioud
Equal Opportunity Employer x:�or�a�asu�+��nFnwaR.aarw�r�an�o�oa��•�
Cerhfica�on
I hereby certify that this plan, specification, or report was prepared by me
or under my direct supervision and that I am a duly licensed professional
engineer under the laws of the State of Minnesota.
Todd E. Hubmer, PE Date
Lic. No. 24043
i��1�1Q��� 7
Paul M. Hudalla, PE Date
Lic. No. 42803
R.��ara� stamwahr rrearm.ne r-.a:twUty a.porr
TfF DJsMct 3
Brookl�m Cent�r, M/n�esota
WSB Projeet No. f 143-03
TABLE OF CONTENTS
1.0 INTRODUCI'ION/PURPOSE ..........................................................................................1
2.0 EXISTING CONDITIONS ...............................................................................................2
3.0 PROCEDURES METHODS ........................................................................................3
3.1 Stormwater Ponds ..................................................................................................3
3 .2 Infiltration Basins ..................................................................................................3
3.3 Raingardens ...............................................:............................................................4
3.4 Undergronnd Stormwater Treatment Devices ....................................................4
4.0 IMPROVEMENT OPTIONS ...........................................................................................6
I 4.1 Option 1— Firehouse Park Treatment Device .....................................................6
4.2 Option 2-- Regal Theater Treatment Device .......................................................b
4.� Option 3—Lateral Storm 5ewer Treatment Devices ...........................................7
5.0 RECOMII+IENDATION .....................................................................................................8
ApPendiz A
Figures
Appendix B
Cast Estimates
Appendiz C
Benefited Areas of the TIF District 3 Regional Treatment System Option 2
Appendiz D
WMWMC Staff Comments on TIF District 3 Regional Treatment System Option 2
a.prond sto.mwatMr rn,rm.n: Fwsraarty R.pori
Tlf Dlsblc! 3
Brook/yn Centa, Minnssadr
I WSB Pro/sct No.11�3-OS
1.0 INTRODUCTION/PURPOSE
Over the next several yeazs, the City of Brooklyn Center is planning to redevelop portions of
TIF' District 3 and to reconstruct streets and utilities within a significant portion of the region
serviced by the 65`� Avenue stormwater system. Stormwater runoff generated in this region
currently receives little or no stormwater treatment prior to being discharged inta to the
Mississippi River. The anticipated redevelopment and street improvement projects provide
opportunity to address, plan, and implement stormwater quality improvements for the
region.
This report identifies and evaluates options available to provide starmwater treatment for
TIF District 3 and the associated 65�` Avenue stormwater system. Background information,
including preliminary redevelopment plans, the City's Comprehensive Surface Water
Management Plan, electronic storm sewer and road profiles, record drawings, and drainage
design calculations were provided by the City. Based on this information, several options
such as ponding, infiltration, and inline treatment systems have been evaluated.
These options, as well as the long-term redevelopment and stormwater management goals of
the City, have been discussed with City Staff and Staff of the West Mississippi Watershed
Management Commission (WMWMC). Information obtained from these discussions has
been incorporated inta the evaluation of options so that the report presents the most cost
effective treatment solutions to address water quality needs of the region.
R�yrorw� srorn,wrr.r rn.tma�r rwswnrry Raport
rrF asu� s
Brnoklyrt Cantu�, M/nn�sota
W58 ProJ�ct No. f1�3-OS pegs 1
2.0 EXISTING CONDITIONS
Approximately 501 acres of developed land witlun the central portion of Brooklyn Center,
includin a ortion of TIF District 3 aze serviced b the 65`� Avenue storm ter stem.
g P Y SY
This system consists of a 60-inch trunk storm sewer that begins at the intersection of Shingle
Creek Parkway and Freeway Boulevard. The sewer continues east along 65m Avenue where
it eventually outfalls to the Mississippi River through a 78-inch trunk storm sewer line. The
majority of the contributing flow is from local streets, residential, industrial and cominercial
land uses adjacent to 65�' Avenue. Additianal flows from approxitnately 130 acres of land
located south of I-694 flow north under I-694 throu�h a 48-inch pipe ttiat discharges into the
65`� Avenue system. In large rainfall events, the 65 Avenue system also may receive
overflow runoff from Shingle Creek.
The drainage area tributary to the 65�' Avenue stonn sewer system west of Highway 252 is
illustrated on Figure 3 of this report and boundaries of TIF District No. 3 are shown on
Figure 5.
It is estimated that only 64 acres within ttus watershed receive some sort of stormwater
treatment before dischazging into the tnu�k system an b5�' Avenue. The remaining 437 acres
drain to the 65�' Avenue syst�m with no runoff treatment provided prior to discharging into
the Mississippi River.
Rpiona/ siormwatrr rnstmsnt FstalWUty R�port
TfF OtsMct 3
8rooklym C�rthr, Mfnn�sota
W5B ProJect No.17�3-OS �Ds Z r
3.0 PROCEDURES METHODS
Four different methods of stormwater treatment including stormwater ponds, infiltration
basins, raingardens, and underground stormwater �eatrnent systems, were considered in
specific locations based on available land area, drainage area, existing storm sewer
co�guratiun, cost, and effectiveness.
Each of these methods of stormwater treatment offer benefits for water quality and may be
suitable to use under certain site conditions. The characteristics of each method and design
criteria used for this analysis are outlined below:
3.1 Stormwater Ponds
Stormwater ponds, also referred to as wet ponds or NURP ponds, aze areas of open
water that capture urban stormwater runoff. Common pollutants such as total
suspended solids aud phosphorus contained in the runoff are allowed to settle in the
ponds. This reduces the amount of pollutants being transported to downstream
waters. Characteristics of stormwater ponds include the following:
Require open space of approximately 3-6% of the contributing watershed
area.
Require that storm sewer be located at suitable elevations to allow Aow in
and out of pond.
Typically remove 40% to 60% of the total phosphorous and 75% to 90% of
the total suspended salids entering the pond.
Skimmer structures at the pond outlet prevent floating materials and debris
&om leavi.ng the pond.
Although several locations were considered for stormwater ponds, it was detern�ned
that construction of stormwater ponds are not feasihle t� treat the flow within the
trunk system. This is primarily due to the storm sewer exceeding 10 feet in deptb
and the limited amount, size, and availability of undeveloped or public land adjacent
ta the 65�' Avenue Storm Sewer System.
3Z Infiltrallon Basu►s
Infiltration basins consist of depressional areas that collect and infiltrate stormwater
nuioff inta the soil. This reduces stormwater runoff volumes and pollutants
discharged downstream and, therefore, improves water quality and reduces chances
of flooding in the area. Characteristics af infiltration basins include the following:
R.ylor,al stom,waea� rrwt►n.n: r-saala��ny �orr
T/F D1sMct 1
Brooklyn Cent�r. INinnssots
IKSB Projsct No. 1143-05 3
Treat runoff directed to basins by infiltrating the retained water into the
ground and removing 100% of total phosphorus and total suspended solids.
Requires open space suitable to collect, store and infiltrate water &om the
tributary watershed.
Cannot be utilized in locations where groundwater contamination may occur
or where high ground water elevations exist.
A majority of the drainage area for the 65�' Avenue storm sewer system is located in
the City's Drinking Water Supply Management Area.. The Cifiy generally
discourages the infiltration of high volumes of urban runoff near municipal water
supply wells to avoid potential contamination of the City's drinking water source.
Due to the storm sewer exceeding lU feet in depth and the limited amount, size, and
availability of undeveloped or public land adjacent to 65�' Avenue, it has been
determined that the use of infiltration basins is not the best regional treatment
solution in this azea.
3.3 Raingardena
Raingardens are depressionallandscaped areas created on a site-by-site basis that
encourage infiltration of stormwater runoff. They provide water quality treatment
and volume reduction through plaz►t uptake and infiltration. Characteristics of rain
gardens include the following:
Natural vegetation can be established in raingardens to create landscaping
amenity.
Promotes groundwater recharge and provides rate and volume control for
sma.11er rai.nfall events.
Not suitable for locations where groundwater contamination may occur or
where high ground water elevations exist.
Raingardens are currently being constructed in the Riverview neighborhood. The
success of this praject should be evaluated over the next several years to determine if
the City would like to pursue additional raingarden projects.
Although raingardens provide infiltration and retention of surface runoff for smaller
areas, regional treatment facilities are a more efficient practice to utilize when there
is a feasible option for regianal improvements.
3.4 Underground Stormwater Treatment Devices
Underground stormwater treatment devices are structural systems connected to storm
sewer to treat stormwater runoff. These devices include proprietary products such as
Vortechnics, DrainPac, Stortnceptor, atid Hydrokleen. The systems, generally made
R�ionN Stomtw�tbr Tnabnsnt Ftss/bfllty Repart
T!F DlsMet 3
Brooklyn C�ntsr, Mlnn�sota
WS8 Proj�ct No. 1143-OS Pa� 4
with concrete, utilize gravity and the stormwater flow to settle and trap particulate
matter in the device. In order for these devices to function, particulate matter must
be removed from them periodically.
Can be installed at various depths and in relatively small azeas.
Typically provide 40°/a to 80% removal of total suspended solids for a
specific design event.
Typically provide 10% to 30% removal of phosphorus.
Ideal for use in developed urban azeas where land is not available to
accommodate other BMPs such as large stormwater ponds.
Due to the limited amount of available public land and the depths of existing storm
sewers, underground treatment devices are the most cost effective, feasible option to
treat stormwater runoff in the subject areas. Several possible locations for
underground treatment devices have been identified and are outlined in Section 4 of
tbis report followed by recommended aptions for stormwater treahnent in Section 6.
For the analysis performed in this report, the design treatment flow rates have been
determined based on runoff from impervious areas for a one-inch (1.0), 24-hour
storm event. Based on conversations with the Minnesota Clirnatology office, this
event will provide treatment for up to 90% of all rainfall events that occur annually.
The water quality devices have been sized to remove approximately 80% of the total
suspended solids that drain to the devices for the (1.0 inch) storm event. In addition
to treating design flow raies, fhe devices will be designed to convey the peak rates
generated by a 10-year, 24-hour storin event which is consistent with the City's sto�n
sewer design standards. These l0-year flow rates for the storm sewer systems were
determined based on drainage areas pmvided by the City.
R�ona/ Stormwata� Tieatment Fw,sibNity Report
TIF D/aMct 3
Brooklyn C�rtt�r, Minnasatn
N/SB ProJect No. 1743-OS S
4.0 IMPROVEMENT OPTIONS
Three options have been developed to treat runoff from a portion of TIF District 3 and other
areas contributing to the 65`� Avenue trunk storm sewer system. Options one and two
consider using underground stormwater treatment devices at one Iocation to treat the
stormwater flowing through the trunk system, and Option 3 considers constructing a device
on each major lateral where it connects to the trunk storm sewer. Wet sedimentation and
infiltration ponds were not viable options given the amount of available lands, the depths of
the existing storm sewer, and the size of the drainage azeas in which they would serve.
4.1 Option 1— Firehouse Park Treatment Device
Option 1 provides an underground treatment structure east of the 65�' Avenue intersection
with Dupont Avenue that services a contributing drainage area of 372 acres. The trunk
storm sewer at this location is a 66-inch pipe that is 25 feet below ground. This treatment
option will treat a significant ruaoff area and requires only a single location for maintenance.
The device would be located within Firehouse Park adjacent to the 65'� Avenue
reconstruction project and would not require purchase of additional land.
Appendix B provides a detailed cost estimate for this option. Implementation of Option 1
would require the removal of several mature trees from Firehouse Park. This report does not
assign a specific cost to the aesthetic irnpact to Firehouse Pazk due to the constructian
requirements of Option 1. See Figure 1 for a map indicating the location of the treatment
device and the drainage area treated by this option.
4.2 Option 2— Regal Theater Treatment Device
Option 2 provides an undergraund treatment device located southeast of 65�' Street and
Camden Avenue in the Regal Movie Theater parlcing lot. At this location the device is able
to treat a contributing area of 493 acres. The tnuik storm sewer at this location is a 72-inch
pipe that is approximately 18 feet below ground. This treatmeat option removes total
suspended solids &om a significant runoff area and would require only a single location for
maintenance.
Fw�thhermore, the location is ideal for maintenance procedures since the site is aa apen
parking lot with little traffic during maintenance crew working hours. Although this option
offers several benefits, an easement to host the device wili need to be acquired from the
nwners of the pazcel.
Appendia B provides a deta.iled cost estimate for this option. See Figure 2 for a map
indicating the location of the treatment device and the drainage area treated by this optiott.
R�pJonai 5twmwat�r 1Ywtmaft Fessiblllty R�poR
T!F Dlsblcf 3
8rook/yn C�nt�r, Mlnn�sots
WS8 Profect No. 1143-05 B
4.3 Option 3—Lateral Storm Sewer Treatmeat Devices
Option 3�provides five underground treatment devices on the five major laterals that connect
to the 65 Avenue t�runk storm sewer line. These devices would treat a total tributary azea of
25S acres. These lateral storm sewer sizes range from 18 to 36 inches diameter with a depth
ranging from 8 to 16 feet deep.
This option provides treatment for a large drainage area and keeps the majority of the
construction within right of way areas on the 65"` Avenue corridor. Maintenance will need
to be performed on each of the devices to remove accumulated sediment as needed. Since
there are mare treatment devices in this option than the other two options, it can be expected
that the maintenance costs associated with Option 3 will be higher than other treatrnent
options.
Appendiz B provides a detailed cost estimate for this option. See Figure 3 far a map
indicating the location of treatrnent devices and drainage areas treated by this optian.
Option 3 would not receive runoff from the City's I-694 redevelopment site.
Table 1 provides an opinion of cost for the three options presented to pmvide regional stormwater
treatrnent for TIF District 3 and the associated 65�' Avenue hunk storm sewer system.
Table 1
65� Avenus Stormwater Treatment Options
Opinion oi Cost
Drainaga 1'��k,��' i�' z�, y
c ��6$ CrUI'Y9' A �.it0�� �1 �a i t`�F,g,� i i� A ���'�i �t r s
T�ted Number Pipe Si�� Inve�t Nr O�A�R�
�io�$ fAcFSS GN l(ttc�il lEeet) �t��► �'�r�a�:
Option 1 378 78 1 2�.4� ��,Q�V �r! 'W'F�i'R'�� nf
Option 2 I 493 I 80 72" I 18.4' 1�S�`54:t100 l'�' ��:5�
Option 3 $22�000
#1 81.8 90 36" 15.9' $260,700 $3,187
#2 14.0 79 18" 8.0' $103,400 $7,386
�3 79.2 68 36" 14.5' $113,300 $1,431
#4 28.5 76 36" 11.6' $113,300 �3,975
#5 50.5 78 30" 9.0' i 13, 300 $2,?44
T�TAL 254 N!A N/A N/A 3�28,OQQ �52;858
Replonal Sior+nwat�r Tnalm�nt Feasibilliy Raport
TIF DlsMct 3
Brook/yn Gnter, Mlnnesop
W5B ProJect No. 1111-OS Page 7
i
5.0 RECOMMENDATION
Section 4.0 of this report outlines the stormwater treatment options for TIF District 3 and the
associated 65�' Avenue stormwater system. The recommendations presented here are based
on our investigation of the existing stormwater system, costs associated with improvements
and discussions with City and WMWMC staff regarding the long-term stormwater treatrnent
goals of the City and the Commission. The recommendations aze as follows:
It is recommended that the City consider Option 2 as outlined in Section 4.2. This option
provides an underground stormwater treatment system i� the movie theater parking lot arid
will provide treatment of stormwater runoff from the lazgest drainage area, including the
City's I-694 redevetopment site.
In addition to treating the largest area, this option also pravides the best access for future
ma.intenance of the system; it is located in an area that has little traffic during maintenance
crew working hours. Furthermore, since there is only one underground treatment device for
this option, cosis associated with maintenance will be less cost�y than having several systezns
to maintain.
It is estimated that capital expenditures to construct Optio� 2 will be 3% more than Option 3
and 15% more than Option 1. When considering the additional area treated by Option 2, it is
clearly the most cost-effective option per acre of drainage area served.
It is recommended that the City work with the provider of the treatment devices to minimize
costs associated with constructing these improvements.
It should be noted that an easement will need to be acquired from the owner of the movie
theater parcel prior to purstting this option. City Staff and the Owner have been in contact to
negotiate a fair price for the easement. It is anticipated that easements for the project will
cost approximately $22,000.
This treatment system will provide total suspended salids treatment equivalent to NURP
ponding for 360 acres (see Appead'u C�. The WMWMC is currently reviewing a proposat
to confirm that they would honor this improvement in lieu of panding for future
developmendredevelopment activities within the Cifiy. See Figure 4 for a map indicating
areas that would meet WMWMC's water quality requirements under this proposal.
WMWMC is currently reviewing this proposal and formal action will be taken by the Board
of Commissioners at their duae 14'� meeting. Comments from WMWMC staff that were
available are included in Appendiz D.
Although this optian will remove a significant portion of pollutants, it will not reduce runoff
volumes. Therefore, it is also recommended that the City encourage redeveloping parcels to
incorpora#e BMPs such as infiltration basins, raingardens, or enhanced ponding techniques
into their site design when fcasible.
Rplonal Stormwator Troatm�nt Faisiblliiy R�pori
nF a�nr�r s
Brook/yn GnHr, Mlnnssot�
WS8 ProJect No. 11s3-OS Pa�s 8
It is concluded that these options are feasible, necessary, and cost effective from an
engineering standpoint as recommended in this report. The proposed improvements are
necessary to provide stormwater treatment prior to discharging stormwater to the Mississippi
River. It is aur recommendation that the improvements provided in Section 5 be constructed
as summarized in this report.
Rp/ona/ Stormwater Trsstma�t FesslWlky R�port
TtF DisWct 3
8rook/yn c�nier, Mlnn�soa
W5B Project No. f 143-QS P�° 9
Appendix A
Figures
R�lortal Stortawahr Fn�tm�nt FssslbfUry R�port
T!F DlsMet 9
Brooktyn Center, Mlnnesots
W58 Profect NO. 11I3-0s
...�..,�..�,.:,..a�
k 'k ,i�y''�A
�yC� a
t r t t o J.� ��F
ti r 4 J' .t
;F f r
1 r+�"
Lr "'E i.,�:.
F
i
I
'I
k Leaend
1.:�. ��k
sw�,� s�
�i. �s..�.
w
L
1 Treatment Nea I
�c'?lJ;l�-�'•l� �i��
Troe4neM Device �I
j i
TREATMENT PIPE
AREA ACRES CN SIZE DEPTH
TOTAL 378 I 78 66" 25.2'
TIF District 3 Regiona/ S!`ormwafer Treatment System Opfion 1 N Figure 1
for
City of Brooklyn Center, Minnesota E
�Ctty ojBronklyn Centtr O $�0 1,� 2.�� //�SB
Af+'I��N�uroNerLAf�MSttbab/h% �FBBt S
d.wpdrs. de.
f�:KtlIW t.rt�L/I�Il10NIk1Y1Y
.�Y:
r+
a
��E r
�f
1
P Z3
Le�
i�
i
Treatment Device
f����:. a�t"..
�ir Storm Sewer
C��
Q TreatmentArea
�'��+a�
TREATMENT PIPE
aREA ACRES CN SIZE DEPTH
TOTAL I 493 801 72" 18.4'
TlF District 3 Re ional Sformwater Treatment S stem O tion 2 N F'9'"� 2
g A
Y
for
3 c�e�orB��,� cene�� Ciry of Brooklyn Center, Minnesota E //�/SB
Af�+nlsce ro srert A �ie.r y!•ce w.tas� 0 800 1�0�0 2,000
Feet S e +mc ar
�..�...�,w�.wr�
t:
r e �.7' E r.
.i t'��si
l�� Q. 1� y�.� V .�.e'� jq�
#T r �Y ,�:'t,�_
`y 4 g• 1 t"„�, p�`���,� �t t
��r�£ f 1 y..y 1•. li�. t c �:f+
—=Y V� .r �R i �r rt
r t t f.
`i i';`1 r f
-�+:�f_ �,+3 t
�k��l
i
'f
L�e end
I stomn Sewer i
T Existin Treatment Area
�r ,Y., 9
i ,»-r Proposed Treatment Area
Treatment Device
DRAINAGE PIPE
AREA ACRES CN SIZE DEPTH
#1 I 81.1 90 36" 15.9'
I #2 15.2 79 18" 8.0'
#3 I 79.2 68 36" 14.5'
i #4 I 28.5 I 76 36" I 11.6'
#5 I 50.5 78 I 30" 9.0'
i
TIF District 3 Regional Stormwater Treatment System Option 3 N F�9'�� 3
for
City of Brooklyn Center, Minnesota E
�City of 8rooklyn Center 0 300 600 1,200
AlMOI P�ate a A�R A!+'�� Il�tt b M�% FP•@ S
Q.Is�a.iaeu. Lr.
fiX �n�m/.YYM,IW�:IF11lM
Le end
Treatment Device
TreatmenG4rea
Storm Sewer
Water Quality
TreatmeM Credit Area
s Y P�
�r.
t
f
::i
q
1.
k
1
r.
r
r
p.: i w
C. r,
t t
°�'t
l�.� Eecb Treatment Credit is far 1 acre of land
Mat maets WMWMCs rules for water qualily
�;r; due to construction of proposed VealmeM device
•:r;
v►oposed vea►menl device wi� provida Sso
r" treatrnenl aedks ta tl�e areas as i�fcated in this
:�.i F�
WMWMC Water Qualify Treatment Credits
TIF District 3 Regional Treatment System Option 2 N Figure 4
for
3 c�riot�lr� c�n«r City of Brooklyn Center, Minnesota E �/SB
,��.eeW■e.ro+r..+..+R...+N.�.ror•y. 0 500 1.000 2,000
Feet
S e �..o�arclnc.
4, 1t�..1t-['_i?yIILa,.r- ,-Jn: Y�. '�''i+.l�
.0 .�1�:75: 7 .-n 1'' y �i,
i i{t..i..,}T_ .r� k._1
y �'��L: �r.� �fiLLII
GC �.S
_I�r��_ TJ;����,�'' I
�.L':�.
�__i C
c .m _._.,i. f`Y?� �LIIIIIIi `1 t� s.
n� t
i �r
t ,.1� i
's---
_n:�
i
�\�'.TlTiiilrl�iill:mr.7 �py�� t __._I
tf ��T' r
i�iLI11J' ��e��� it7trt i ��t�
sar
''�t�'�' nzr��Z',
�7��-�y�
4
".i S ��ti.II"u:.IIi! �-n�� .•yIt
V'
T
J
�1t:.
i:
�i
���p
`"L.._--
i ,r :�r�;
�-�1������. ;f
�����1��1����
.r c__ Legend
TIF District �2 #3
�___J none #3 #3
#1 #4 #3
Figure 5
City of Brooklyn Center TIF Dist�i.cts
City of Brookdyn Center w/s'B
A great place to start. A great place to atay.
�,luo�raru. L�c.
J
Appendix B
Cost Estimates
Rp/onal StormwstN' Tiwtm�nt FesslbJ/Ny Ropart
TIF DlsMct 3
Brookhm Csnt�r, M7nnssob
WSB ProjeciNo. 1143-OS
Strormwater Treatment Feasibility Report
Feasibility Report
TIF District 3
OPTION 1 Treatment Devices at Dupont Ave d� 6Sth
Item Duantita► Units Unit Cost Cost
Mabilization I 1I EA I $20,4001 $20.OD0
Vortech 2538 CIP I 21 EA I �220.0001 �440;000
�pass MH (f 0' Dia) 21 EA I $25.0001 $50,000
Storm Sewer I 1 I LS I $25,Q001 $25.00�
Restoration of Site I 1 I LS I $55,9091 $55,909
Subtotal $59Q,909
10% Contingency $59�091
Totai assa,000
Strormwater Treatment Feasibility R+eport
Feasibiilty Report
TIF District 3
OPTION 2 Trostment Dsvicss at Movfe Theatar Site
Item Quantity Units Unit Cost Cost
Mobilization I 11 EA $20,0001 $20.000
Vortech 2943 CIP I 21 EA I$25Q,0001 $500,000
Bvpass MH (10' Dia) I 21 EA I �30,0001 $60,000
Restoration of Site I 1 I LS I $6� ,7981 �50,OOQ
Sanitarv Sewer I 1 I CS I $30,0001 $21,818
Storm Sewer I 1 I LS I $30,0001 $30,000
Subtota! $681,818
10% Contingency $68,182
Total $750,OQ0
Note: EasemeM acquisi�on costs not included but are an�cipated ta be appraximately
a22,000.
Strorn�water Treatment Feaslbility Report
Feaslbility Report
65th Avenue System
OPTION 3 Troatment Devices on Lateral Lines
Treatment
Area Item puantit�/ Units Unit Cost Cost
Mobilizataon 1 I EA I S20,Q001 S20,OD0
PC 1319 qarratlei I 21 EA I 105.000.001 $210,000
BY�ass MH {72" Dia) 21 EA I 7,000.001 $14,000
1 Restoration I 1I LS I 5,000.001 �5,000
Storm Sewer I 11 LS I 8 �8,000
Area Total I $237,000
VX1600 offline I 1 I EA I 76,000.001 $76,OQ0
Bvpass MH (48" Dia) I 21 EA I 5.000.001 $10;00�
2 Restoration I 1l LS I 5,000.001 $5.000
Storm Sewer I 11 LS I 3,000.001 $3,000
Area Totat I �94,Q00
VX1600 offline I I EA I 7s,oao.oai $�s,000
�ass MH (72" Dia} I 2� EA 7,000.00� $i4,000
3 Restoration I 11 LS I 5,000.001 $5,000
Storm Sewer I 11 LS I 8 �8,000
Area Total I �103,000
VX1 fi00 offline 1 I EA 76.00O.00I $76,000
�pass MH (72" Dia1 I 21 EA I 7,000.001 $14,OOU
4 Restoration I 11 LS I 5,000.001 $5,000
Storm Sewer I 1 I LS I 5,000.001 $8.000
Area Total �103,000
1421 CIP online 1 I EA I 95A00.001 �95,000
5 Restoration I 11 LS I 5A00.001 �5.000
Storm Sewer I 11 LS 3,000.00� $3.000
Area Totai s10S,000
Subto#al $6fi0,000
10% Contingency $66,000
Tot�l $726,000
Appendix C
Benefited Areas of the TIF District 3 Regioaal
Treatment System Option 2(submitted to WMWMC)
Raplonal Stamwahr Tnstin�nt rwslblllty Rsport
TIF OisMct 3
Brook(yn Csnhr, Minn�.sots
WSB Propct No. f1�3-OS
WSB
d.rsociares, lnc. tinfrastructure Engineering 1 Ptanning i Construction 701 Xenia Avenue South
I Suite 300
Minneapolis, MN 55416
June 4, 2007 rei: �s3-�a�-asoo
Fax: 783-541-1700
West Mississippi Wat�rshed Management Commission
clo Ed Matthiesen
Wenck Associates
1800 Pioneer Creek Center
P.O. Box 428
Maple Plain, MN 55359
Re: TIF District 3 Regional Stormwater Treatment System
WSB Project No. 1143-OS
Dear Mr. Matthiesen:
Thank you for #aking the time to meet with City of Brooklyn Center (City) and WSB staffto discuss
regional stormwater treatment improvements that the City is currently planning. As discussed at
these meetings, the City is proposing to construct an underground stormwater treatment system on
the Regat Theater Site located at the northwest quadrant of the Highway 252 I– 694 inierchange.
This treatment device will service a contributing drainage area of 493 acres; see attached Figure 2
for a map of the contributing drainage area.
The attached report entitled, "Benefited Areas of the TIF District 3 Regional Treatment System"
outlines the design of the proposed system and the extent that the treatment system will satisfy the
West Mississippi Watershed Management Corncnission's (WMWMC) rules for future development!
redevelopment withixi the City. The City requests that WMWMC approve the proposed treatment
system as presented in the repart at its upcoming meeting an June 14.
If you have any comments or questions, please contact me at 763-287-7176.
Thanlc you for your time and attention.
WSB Associates, Ina
i�i�'l�l���:.�''`
Paul M. Hudalla, PE
Attachment
lh
Minneapolis 1 St Cloud
Equal OpportunitY E�i�lN3-osumn�nw��wa�s+�+�urm�tzx-.an�au�eu�+e�as.ionzao�
BENEFITTED AREAS OF THE TIF DISTRICT 3
REGIONAL STORMWATER TREATMENT SYSTEM
Prepared For
City of Brooklyn Center
June 4, 2007
CERTIFICATION
I hereby certify that this plan, specification or report was prepared by me or under my direct
supervision and that I atn a duly Re�isttred Professional Engineer under the laws of the State of
Minnesota.
0�2.f'�f.� L��� u 7
Paul M. Hudalla, PE Dats
Lic No. 42803
S�Y�7
T�d E. Hubmer, PE Date
Lic No. 24043
B�nMbd Anas ot tfw 71F QisMct 3 Rploeal Sbom�wabr Troabn�nt Sysbm
City of Brookly� C�nt��, MN
VYSB Projsct No. 1143-OS
TABLE OF CONTENTS
I INTRODUCTION ..............................................................................................................1
II. FEASIBILI'I'Y STUDY SUMMARY 2
III. DESIGN PARAMETERS TREATMENT SYSTEM EFFICIENCY 3
IV. WATER QUALITY TREATMENT EQiJIVALENTS 4
V. LOCATIONS THAT WILL UTILIZE THE PROPOSED SYSTEM TO MEET THE
WATER QUALITY REQUIREMENTS OF TI3E WATER5HED S
List of Tables
Table 1 NURP 50 Total Suspended Solids Distribution
List of Fi�ures
Figure 2 TIF District 3 Regional Stormwater Treatment System Option 2
Figure 4 WMWMC Water Quality Treatment Credits Due to Construction of TIF District 3
Regional Stormwater Treatment System Option 2
Append'ur A Contech Technical Documentation
Bsrnflted Arsas of th� TIF District 3 R�pional Ston»wat�r Tnatm�M Sysbm
Cfty ot Brooklyn Gnbr, MN
WSB Project No. 1143-06
I. INTRODUCTION
This dacument has been e ared to resent the technical information associated with
Pr P P
construction of a proposed regional stormwater treatrnent system to service TIF District 3
in Brookiyn Center, NiN. A summary of the Feasibility Study and the recommended
system is provided as well as documentation supporting the design parameters and the
efficiency of the treatment system. The document also outlines the extent that this
treatment system will satisfy the West Mississippi Watershed Management
Commission's (WMWMC) rules for fitture development/redevelopment that is
anticipated to occur within the watershed tributary to the proposed impravement. Finally,
the document outlines areas within the City where water quality requirements of the
WMWMC will be met by the proposed treatrnent system.
@sn�flNd Aroas of ths TIF �isMct 3 Reglonal StortnwaLar Tr�atmont 8ystsm
Ctty oi Brooklyn C�n�r, MN
WSB Projsct No. t143-05 Page 1
II. TIF DISTRICT 3 REGIONAL STORMWATER TREATMENT FEASIBILITY
STUDY SUMMARY
Over the next several years, the City of Brooklyn Center is planning to redevelop and to
reconstruct streets and utilities within a significant portion of the region serviced by the
65�' Avenue stormwater system. Stormwater runoff generated in this region currently
receives little or no stormwater treatment prior to being dischazged into to the Mississippi
River. The anticipated redevelopment and improvement projects provide opportunity to
address, plan, and implement stormwater quality improvements for the region.
A feasibility study for stormwater treahnent of this watershed has been prepared by WSB
for the City oP Brooklyn Center. This study identified several options for stormwater
treatment. Of these options, an underground treatment system appears to be the best
option from a cost and constructability standpoint for regional treatment aad is
reconunended ta be constructed in fall of 2007.
The system is proposed to be located just to the easi of 6S�' and Camden Avenues in the
Regal Movie Theater pazldng lot. At this locatiott the device is able to treat a
contributing area of 493 acres. The trunk storm sewer at this location is a 72-inch pipe
that is appro�cimately 18 feet below ground. This treatment option removes totat
suspended solids from a significant nuioff area and would require only a single,
convenient location for maintenance.
The report concludes that construction of the treatment system is necessary, and cost
effective from an engineering standpoint.
Bensfltsd Aroas M th� T{F District 9 Rplonal Stortnwater Tnatmont System
City of Brooklyn CantK, MN
WSB Project No. 1143-05 P89e 2
III. DESIGN PARAMETERS TREATMENT SYSTEM EFFICIENCY
Several design parameters were considered to determine the appropriate size and
associated efficiency of the proposed treatment system. Paratneters cottsidered include
the following items:
Drainage Area Treated
The drainage azea treated by the proposed system is 493 acres. This azea was
determined by WSB using sewershed delineations provided by the City.
Treatment Flow Rate
The treatment flow rate for the proposed system is 85 cubic feet per second. The
treatment flow rate is defined as the maximum flow rate in which the treatment
system is designed to remove TSS from flows. This rate has been determined
based on runoff from impervious areas for a one-inch (1.Q), 24-hour storm event.
Based on conversations with the Minnesota Climatology office and available
rainfall data, this event accounts for more than 90% of all rainfall events that
occur annually. A calculated curve number of 80, an estimated 84-minute time of
ods were used to deter�nine the flow
concentration, and NRCS hydrology meth
rate.
BYPass Flow Rate
The bypass flow rate for the proposed system is 372 cubic feet per second. The
bypass flow rate is defined as the maximum flow rate that the system can convey
without resuspending TS S that has been retained in the system. The rate was
determined assuming full-flow conditions of the existing storm sewer main
upstream of the proposed system (72-inch pipe, 0.77% slope, Manning's
roughness coefficient of 0.013).
TSS Particle Distribution
TSS particle distribution used to design the proposed system is a 50 micron
gradation as shown in Append'u A. This particle distribution closely resembles
the NURP 54 particle distribution that has been provided by Wenck Associates as
indicated in Table 1. The 50 micron gradation oniy considers particles under 75
microns. Therefore, the 50 micron gradation does not have the larger particles
included in the NURP 50 particle distrihution and will provide a more
conservative design than recommended by the WMWMC'sBngineer.
The treatment system is proposed to consist of two 29 by 43 foot treatment structures
placed in parallel. A bypass structure is also proposed to divert treatment flow rates into
the treatment devices and to atlow higher flow rates to bypass the treatment devices.
Based on this proposed design and the previously discussed design parameters, the
treahnent device manufacturex has determined that the proposed system is able ta remove
69% of the TSS flowing through the trunk storm sewer line. See Appendiz A for design
and testing documents provided by the manufacturer of the system.
B�n�flt�d Anas of tM TIF DlsWct 3 R�pionsl Stormwatsr T►�aemant Sysbm
City of 8rooiclyn C�M�r, MN
WSB Project No. 1143-05 Page 3
IV. WATER QUALITY TIt�ATMENT EQUIVALENTS
The Watershed has established rules that uire develo ments to rovide stormwater
reQ F P
treatment ponds that meet the Nationwide Urban Runoff Program (NURP) standards for
stormwater treatment. Since these rules da not specify requirements for underground
treatment systems such as the one proposed, the City and WMWMC staff have agreed
that equivalency of the proposed treatment devices compared to the WMWMC's rules for
ponding should be determined through a comparison of treatment removal efficiencies
that can be expected from the systems.
WSB has prepared a water quality treatrnent equivalency analysis to determine the extent
that the proposed treatment system will satisfy the �JIVIWMC's rules for development
and redevelopment proposed to occur in the City. The ana.�ysis is outlined belaw in a
step-by-step fashion:
Step 1: Determine TSS Removal Efficiency of NURP Ponds (Required by
VVVZ1�iWMC)
85°/u TSS Removal assumed for NURP ponds
This analysis applies to the removal efficiency io 100% storm event
Over subject area (493 acres), removes TSS runofF from 419 acres (493 x 85% x
100%)
Step 2: Determine TSS Removal Efficiency for Proposed Treatmeat System
69% TSS Removal per manufacturer's calculations
Applies to greater than 90% of rainfall events
Treatment structure sized to service entire 493 acres
Over subject area (493 acres), removes sediment runoff from 306 acres (493 x
69% x 9�°/u)
Step 3: Compare Removal Efficiencies of NURP Ponds vs. Proposed Treatment
System
Based on TSS removal ratio between proposed treatment system and NURP
ponds over the subject azea (as determined in Steps 1 and 2)
Treatment Ratio 306 acres 419 acres 73%
Proposed treatment system is 73% as effective as NURP Ponds for TSS remaval
Step 4: Determine Water Quality Treatment Equivalents for Proposed System
Applies the Results of Step 3 to the entire subject area
Proposed treatment system will provide TSS removal equivalent to NURP
treatment for 360 acres of the 493 acre, subject azea (73% x 493 acres)
Based on the results of this analysis, the treatment system is proposed to meet the
WMWMC's water quality requirements for 360 acres of the 493-acre area that drains ta
the treatment device.
Benefibd Anas of tha TIF District 3 Reglonal StortnwatK Tnatm�nt 3ysbm
City of Brooklyn Csnt�r, MN
WSB PraJect No. 1143-05 Page 4
V. LOCATIONS THAT WILL UTILIZE THE PROPOSED SYSTEM TO MEET
THE WATER QUALTTY REQUIREMENTS OF THE WMWMC
Based on the results of the analysis outlined above, the proposed treatment system will
meet water quality requirements of the Watershed for 360 acres of the 493-acre area that
drains to the treatrnent device. The City has identified 360 acres of properties that will
utilize the proposed treatment system for future development redevelopment. A map of
the properties can be found on Figure 4. It is proposed that water quality requirements of
the Watershed wil! be met for all of these properties through construction of the proposed
treatment system.
The map on Figure 4 will be updated as necessary to add or remove pazcels that will
meet the WMWMC's requirements for water quality. The maximum acreage treated by
the treatment device as indicated on the mapping shall not exceed 360 acres. Any
amendments ta the map will be presented to the WMWMC for approval. If WMWMC
rules aze revised with more stringent water quality requirements, another equivalent
analysis will be performed and the map will be revised. The WMWMC will have the
opportunity to review and approve the map as amendments become necessary.
9�nMbd Anas oi th� TIF DisMct 3 Regional StormwaUr Tnatm�M Sysbm
City of Brooklyn Canbr, MN
WSB Project No. 1 t43-OS Page fi
FIGURES
B�n�ftt�d Aroas of th� TIF District 3 Re�tonal StomiwatK Tnstm��t Sysbm
City of Brooklyn Cwnt�r, MN
WSB Project No. 1143-05
TABLES
Bs�stit�d Arsss M th� TIF DisMct 3 R�gional Stormwabr Tnatrn�n! Syst�m
City of Brooklyn Cs�r, MN
WSB Project No. 1143-05
I
Table 1
NURP 50 Total Suspended Solids
Par�cle Distribution
�f�'� f��a�t,�"...� T� '�:i �i
20% 5 8
20% 8 30
20% 30 75
40°/a 75 or �reater
(Based on information provided by Wenck Associates,
derived from NURP 50 distribution)
I
Bmsflt�d Aroas ot ths TIF Distrlet 9 Regionai Stormwatsr TnaUn�rrt Sysbm
Ctty of Brooklyn CaMer, MN
WSB Project No. 1143-05
I
APPENDIX A
Contech Technical Documentation
B�naflt�d Arsas of th� TiF District 3 Rsgional Stormwat�� Tnaem�nt Sysbm
City of Brooklyn Cenbr, MN
WSB ProJect No. 1143-05
ent Systems
Vari�chs TM S�rmwater Treabn
.���-y�---
OW CALCULATIONS
Regal Theate� Site
Brookiyn Center i�����
Modst 2943CIP
a Sr��.
°NS• ...S�stem 1 of 2 2943_CIP 50 micron
„�.-,rt,
Vrt�techs Ort}lce Vortachs Welr �yp�� w.�,[
Cd 0.86 Cd 3.33 Cd 3.3
A(ft�) 5.90 Weir Crest Lenplh (ft) 29 Wsir Crest Length (ft) 3.5
Crest Elevation (ft) 814.92 Crest Elevatian fft1= 819.68 Crest Elevation tfta 878.34
Head I Elavatlon I Oriflce Flow I W.ir Flow M Bvpass Flow Total Flow
I (n) I (ots) I icis). I l�► 1
0.00 814.82 0.00 0.00 M 8.00 O.QO
0.40 B'15.32 2.85 M 0.00 N 0.00 2.85
0.80 I 815.72 N 8.05 M 0.00 I 0.00 I 8A5
1.2d 816.12 14.80 M 0.00 0.00 14.80
1.80 818.52 23.86 0.00 0.00 M 23.88
2.00 816.92 29.16 0.00 N 0.00 N 29.18
2.40 I 817.32 33.64 0.00 N 0.00 M 33:64
2.80 817.72 3T.59 0.00 N 0.00 N 37.58
3.20 818.12 41.18 0.00 N 0.00 41.18
3.42 I 818.34 42.97 0.00 N 0.00 1 42.97
3.80 1 818.52 1 44.44 0.00 N 0.90 45.35
4.00 1 818.92 4T.50 I d.00 I 5.14 I 52.84
4.40 1 819.32 N 50.37 0.00 1126 61.83
4.80 819.72 I 53.09 I 0.86 I 18.79 72.84
5.20 I 82a.12 I 55.66 28:80 I 27.50 I 111.97
5.69 82U.81 N 58.7� 97.89 N 39.82 N t86.�Q
Please note that the above represeM the flow calculatlons �w one trestment unit� the system in parapel would be
flow the„ mal� r le would be 7 ft.
wei
Ce�lated bv' DMP 5/24/2007
The total ipeak for both units is 372 s
r• �6C�C9d.r�_..._._., r- ._i
V«techBTM SyStem
az�.o 1 I I _1
�o.o �.._.--1---...t_.._..tW���
819.0 I
3 .._..�.......�......�._....�......�...•--f BYPass�
818A I I I I I
817.0
I I I
816.0.
I I I I I I
---W
814.0 �------I ------I--- 1------�-- I
I
0.0 20.0 40.0 80.0 80.0 100.0 1TOA 14D.0 180.0 180A 200.0
OfsdwtGe (cfs)
f:ldatalvortechnlprojeds121552 Optbn 2 2943- 50 micron AP 5/25/2007
'rt Systems
Vortechs StormwaterTreatm� .___1�.�.a
VORTECHS SYSTEM NET ANNUAL SEDIMENT LOAD REDUCTI�N EFF#CIENCY
Re ai Theater Site
g '�m����
Brooklyn Cente
Mode119000
N�- �tem 1 of 2 2943 CIP 50 micron
[244.5 acresl x (Q.a1 x (44� aom/cfsl
Deatpn Ratto' a (860.5 s� gg•l
Bypass occu�^s at an elevatfon af 818.3' (at approxtmately 29 ePmis�
RaMfa�ll lntsnsitv Oosratin� Rats �L Total RaiMail Rmvl. Eitcv` �et. Eftcv
"/hr �misf Voluma'
0.02 N 2.0 I 11.696 I 98.0°k I 11.496
0.04 I 4.0 M 10.1'6 I 95.896 I 9.796
0.08 M 6.0 I 8.196 I 92.696 1 7.596 I
0.08 I 6.0 I 6.796 1 90.0% I 6.096 I
0.10 M 10.0 N 6.8% M 87.1 I 5.996
0.12 I 12.0 4.496 I 84.096 I 3.796 I
0.14 14.0 4.296 80.3% N 3.496
0.16 18.0 4.596 1 77.496 I 3.596
0.18 17.9 3.896 1 74.096 I 2.896
0.20 1 7 9.9 1 4.3'� 1 70.996 I 3.196
0.25 N 24.9 N 6.1 64.2°Xo M 3.996
0.30 I 30.1 M 4.196 57.1 I 2•4°R+
0.35 N 32.2 3.2% I 55.096 I 1.796
0.40 I 34.3 I t.496 M 52.496 I 0.796
0.45 M 35.5 1 2.296 M 51.396 I 1.19`
0.50 I 37.5 1.096 M 4A.2% I 0.596
0.T5 I 56.1 M 5.T9�G6 N 25.896 I 1.540
1.00 M 75.7 3.796 N 8.296 I 0.396
!.50 N 113.6 M 2.296 1 0.096 I 0.09fi
2.00 I 151.5 I 0.496 0.096 I 0.096
I 69.196
'K ratn fsiling st >Z"/h� or byp�ssinq traatmant 5.3%
Assumed nmoval �fficiency 1�cr bypasssd flows a 0.096
N�t Annual T8S Removsl Ef(Iciancy a 89X.
;1 Deeign Rat10 =(Totat nrain�e nrea) x(Ru�otf coetRcient) x(cra b�pm cor�version) a�t c�arnber nrea
The Total Drai�rege Area and Rundf CaetfldeM iB sped�ed by the sita enainaer. .1
The cornraraion fac�a from ds to qpm ie 449.
Operatl�6 �(9P�'y� intensity ('Ax) x Deaign Ratb.
8ased on t0 yea►s of houdy predpitation data frort► NCDC site 7284. S� Cloud WSO AP, Shurbume. MN
rtacron oaNdas �sae TechMcal Bull�in #1l.
50
24/�07 �Ghecked bv:
lated bv: DMP 5/ 1
Based
f:�datalvortechniprojects121552 Opaon 2 2943- 50 micron AP 5/25/2007
Vortechs� System Performance:
Removal Efficiencies for Selected Particle Gradations
lhese performan¢e curves are based on laboratory tests using a fuu scale Vortechs' model 20U0. The testing protocol
used is summarized on the following page. The 150-micron curve demonstrates the resuits of tests using particles that
passed through a 8U-mesh sieve and were retained on a 100-mesh sieve. The 50-miann curve is besed on tests of
partides passfng through a 200-mesh sieve and retained on a 400-mesh sieve. A gradation with an average particie
size (d�} oi 80 microns, containing particles r�ging irom 38-500 microns in diameter was used to represent typical
stormwater solids.
Vortechs• System Removal Efficiencies for Selected Partide aradations
80%- �"L•
�80'K-'-----
W
4�Ni""""""'-'-"-"---_'-""""' 1
20%-
'A.���
(0) 10 (7) 20 (14l �0 (Z� 50 (34) 80 (41) 70 (48) 80 (64) BO (81) 100�(88)
OPeretin9 Ra1s yPmAt' (LAn�
gp H y tS0-rtdaon
As the graph clearty shows, CONTECH Stormwater Solutlons systerr� maintain positive total suspended solids (TSS)
romoval efficier►cies over the fua range of operadng rates. This atlows the system to effectiveiy traat all runoff irom large,
i�reguent design starms, as well as nmofT from more frequent low-intensity storms. CONTECH Stormwater Solutbns
systams sre designed to t�eat pe�ak flows irom 1.6 cfs (45 Us) up to 25 ds (710 Us) without bypassing. However,
extemal bypasses can be conflgured to convey peak flows around the systam if treatment capsciry is exceeded. The
CONTECH Starmwater Solutions system can be c�nflgured to direct iow flows from the last chamber of the system
to poUsh�e treatment when mare stringent water quality standards are imposed. In aU conflgurations. high removal
ef�aenaes are achieved during the lower i�tensity storms, which constltute the majority of annual rai�all volume.
CONTECH Stormwater Solutions systems are sized based. on flow rate rather than volume, which alluws affective
treatment of runoff from the en4re storm, including high-intensih+ flows. This design basis addresses the deficiencies
of convendonal volume-hased BMPs, which cepture the first half or whole inch of n.malf hut may bypass prematurely,
allow reauspension of previously captured pollu�nts, and/or wash out at higher flow rates. For more informadon about
the CONTECH Stormweter SoluUons Inc. sizing methoddogy, please refer to Tech�cal Bulletln No. 3.
�y.a.a�.�.�.a,,.�,.
CONTECH Stormwate� Solutions lnt. www.contechstormwater.com
Laboratory Quality Control Brief
The faibwing prof�oco! contains sta�d�rd operating procedures for Total Suspended Solids (TSS) testing in the GONTECH
Stormwater Solutions laboratory. These guidelines were foilowed in the creabon af the preceding performance curves.
Sedime�t Source
Sedimerrt samples are sorted according to ASTM Special Technicai Publication 477 B, which establishes sieve analysis
prxedures. U.S. Standard Sieves in a Gilson 35-15 sieve shaker are used to separate partides to the varbus fradions
required for our tests. To ensure uniformity of those fractions, an unsorted sample is sieved un�l less th� 196 of that
sample passes through the sieve in one minute. Ail sediment recovered afte� a test is d�ied and re-sieved according to
this procedure hefore reuse. Unless othervvise specified, mineral sediments with a density of 2.65 g/cm' are used.
Flow Calibration and Regulations
Flow calibratan is accomplished by calculating the head at the baffle wall required to praduce a given flow rate through
the orifice and the weir in the flow controi wall. Flow is regulated by a 12-indt butterEty vatve located upstream of the
CONTECH Stormwater SoluGons system. In orcler to simulate fieid condi�tions, flow rates are changsd gradualry to avad
flow surges �rough the system. The test flow rate is set by observin� the head in the CONTECH Stormweter Solutlons
system and adjustlng the regula�ng vaive accordingly. Before any samples are collected, tha vaive must remain �xed
for a periad equal to half of the detention time so that 8ow equalizes throughout the system. Each test group is planned
so that flow rates increase incrementally in consecuWe tests.
Sediment Metering
All sedfinent is injected i►rto the inlet pipe via a%s-inch flexible hase using a Wafison Ma�lcw 5058 peristaltic metering
pump. For TSS tests, a known gradation af sediment and water are combined in approximately a'� poundJgallon ratlo
a holding tank and homogenized by a mbcing propeqer powered by a Y: horsepawer motor. The mixer is activated at
least fi�e minutes beFoce testi�g commences and n,ns continuously ttwoughaat the test The mete�p pump is adivated
for.a period of time equal to at least half of the detention Ume of the CONTECH Stormwater Sdudons system at the
test flow rate, before the firsi influent sample is taken. The pump must run oontinuously untif the last eftluent sampie is
taken.
Sample Collection
AH influent samples are taken from a six-inch gate velve located upst�eam of the CON7ECH Stormwater Solutions
syste�m. A collec�on hin housing a 500 mL sample oontainer is positioned beneath the vaNe. Five seconds belore each
sample is taken. the valve is quicldy flpened and d�ed to elimi�ate any interfetence from parades that have setded
in the law velocity region of the gate. This eliminates artificially high influent readings. The time that the influent sample
was taken is recorded and the coResponding eiAuent sample is collected after a period of tlme equ�t to the detention
tune. E�luent grab samples are coUeat�ed at the discharge pipe, by sweeping the mouth of a 5W mL bottle through the
exiting flow stream. Samples are annotated and refigerated unbl they can be analyzed.
Sampie Analysis
TSS samples are analyzed in the C�NTECH Stonnwater Solutions laboratory, foilowing EPA method 16Q.2, a method
for the measurement of total non-fifterable solids. Volume measurements are accurate ta 0.8 mL using a 500 mL
graduated cylinder. M Acculab V 1 anaytical balance with a readability of 0.001 g is used to measure mass.
m.� acwaa7wiaa� ww�r a+wo mr
CONTECH Stormwate� Sotutio�s Inc. www.wntectutormwater.com
t
vortrEais srsre�m
IWaTALIEp IN A BYPAlS �S-0' I13100�
CONf10lNlATION �RE
Atl tIPSTIIEAM OINER810N BEALANT
9TRIJCTURE TUT &MLL AI.UNINUM AN(iLE R.ANOE BAFLE WALL FLOW CONiROL
B! DETAq.� W TFIE
co�xTwci �nar� wrtH Ne�a�ue cu�s�r r w�u
NATN ELLNATION MO
WEIR W Wf11 DATA
aROwoeo ev coNTeCr+ i.:C.' r. o. :1 v w; w s�.r';, �.r .i::::•,'•. f!` s:
BTORIWNATHt80l.IfT10N9. i`.2 r. 3n- s x'
'�Y. pqµ�CE 8
R. r
K�� I
I r:
h ;s
1 y
ri
1 1 R y
w a�.
L�J s.�„�„
't j ?}1
i 3
�'t..�'� Cy.
f 2e'"-m' a�tsl
�---J L--J :t:
t, i
i1 N• .fi�
rt
�'K j fi
r;: L j J �r� f-
a. 7 r,
I s� i;
!0' .:r� i v:
L
A n ii /1
v Sl
l• I �.4
v BEAtANT I 1_
MILETIMV VARY v. 1:_i..; ..w- y:q: �i'.Sk a .g:�::.t ii� .�iaS.;;t„��7±�_...:i' �''.liiii/. R 4�.;+::t ..n�: 011T1ET.
e�e norea a d
8EE NOTE P
PLAN VIEW B B
ItlM ELEVATIONOTO
�eTE WTCM FItA�O GRAOE
F�OLCAGINO��� �W�BVOTHER$
�o:!• :`:X' �:4�,l:.:.
�t� `i�i.+�. "Y j' :y�� i.�"' :it:,{..'
'r.`i A��::. �_q'�:;r� -�y:' �'�...w. �:k.
a`: �yri. Si.:;
I T�
e a A B
�""'"r J.
,ra� �"�T ru�a oun.�r
1
A. �;1
ew[sesy r-0'neml e-0'I��l
M c II
II
;.±aFF. p'.� I:da �.w S' ..Y �.r .y.r:Z.::�+s va ��1�
�l :ij:�..� �f+N�' fT y` wC'.r�tii: :�,.i�f.rv9��rr_.S_..�G:5
SECTION A A
caaa�crEO an�vft
8. 8Wf8 BHALL NOT BE CaAPROAbED BY EffECfB Of DOYYN07AEAM TAIIWATER
1. BTORIMWAT@R TREATM6Nf SYSTEM (51M9J 4YIA41. NAV� 7. 81MT8 81iAL�. MAVE NO IMEANAL C01WOti6NT8'f}MT OSBfTAL1CT iiWNTlNA1�ICE ACCE88
PEAK 111fATMlNT CAP1lC17Y: t4i �(�1l�.6 Wl 0. R�tT RPE MU87 9! PlAPEl101CILAR TO 7T# il'IGJCfURB
SlDIMB1T STORME: N Ct! VO �51.9Y m� l PIpE 014@ITATON MAY vARY: 3Et SIl! PIiW PoR SIiE AND LOCATON
BEONdd/T CFIA�lBt Wil• 2P I!lsYl 1Q PUIlCNA6ER BHALL NOT RqPON81iL! FOR �lB�Ii.Y OF U!�
2 8Wf8 9HN.L BE CONTAIN[D IN OME RdCTANOULM ST1wC7URE 11. AMNF101.E RRAFld ANO P¢RFORATEG CoVH1s �JPPLI� WIZH $YSTEM. NOT e18TALLED
8Wf8 HEMOVIIL �RfaENCY lHI1LL 8H DOCUMENTED MOEC ql PARTICLE BRE tZ PUf�t1A8Bt TO PAEPAtiE EXCAVATION AND PROMpE CRAN! f011 ORF{011dN0 AIW
SWTS ONKL I�TNN N.OATMLEe ANO 711APPED BEOMABiT UP TO ANO SERWO AT 11ML Of OWV�tY
NlfxUqN6 PEJIK TI�+►111@M C�PIK7T1' ri. YORTlCF16 SYSTlM! SY CAWTlCf STORl�AYIIATp180L1111Gi�8: PORiIAiD. OR
S SYVT'8 UIVEfRB M/ NID OUT ARE 1YPICALLY AT 1H[ SAMi 6LEVAl10N �l00�6{i�/Q: SCA�UOM. ME N?'h 90T-lf74lN�'1111QN� MD (!M� 7�G7318.
PROPRIETARY INFORMATION NOT TO BE USED FOR CONSTRUCTION PURPOSES
�n+s um r r br rr awo.. a.p.dywq.a�.ur ew� w�+a� b a wmriw sr ca►�a+a aa�ror mu m.r w+r w r.a�n.e a ow.r mo�wa.say r v�e
er eONT�M aawwr. ss1M�r. nu mr Inannwon...+wM m. ca+TECM e sahren� iooe.na w vart.nr aw.�wrr r. ay�r. a.ra�Mkn.a v+�►numer.
n�rMdiY�dY RwMan�NasYP�dM�CA00Y��WiaMP�amAwd�WMCONTEq/91anwM�r]atMarM�6�awWw�dw�Ar�dnrdpaFMY/yMl�rYm.
STANDARD DETAIL
STORMWATER TREATMENT SYSTEM
STORMWATER VORTECHS� MODEL 2943CIP
SQLV 1 I�NS.. U.B. PATENT Na S.7�Y.H5
�bf.COnl DATE 1?11A! SCALE NONE RILE NAME: 2Y13pP N ONANM: J8S CNHq�:1�O
Appendix D
WMWMC Staff Commenta on TIF Di9trict 3 Re ional
Treahnent System Option 2
Rpiona/ Stormwat�r rrrat►n�n: Fwaibiilty R�port
T1f WsMct 3
8roaldyn C�ntN, M/nn�sota
Wse FroJear No.1 �ss-os
The results of the Feasibility Study plus a Technical Memorandum have been submitted to the
Commission for consideration. It is anticipated that the Commission will act on the submittal at their
June 14, 20Q7, meeting.
Rplonal SMrniwaMr Tiw�lm�nt Fiasiblllty R�port
rw
TlF DfsMc! 3
Brooklym C�nta, Nfnne�sota
W38 ProJ�ct No. 11�3-05
I