HomeMy WebLinkAboutDrainage Reports - 04/30/2018I North Star
�a,,, design
700 Automation Drive, Unit 1
Windsor, CO 80550
Phone: 970-686-6939
Fax:.970-686-1188
April 30, 2018
Heather McDowell
City of Fort Collins Stormwater
700 Wood Street
Fort Collins, CO 80522-0580
RE: Drainage Addendum to the "Final Drainage Report for the Seventh Filing of
the Centre for Advanced Technology"
700 Centre Avenue
Dear Heather,
I am pleased to submit this drainage addendum in conjunction with the minor amendment for this
site for your review and approval. This drainage addendum serves to summarize the drainage
design of the'Summitstone Health Partner project. This letter will detail the effect of the proposed
improvements for the site and show that the site complies with the drainage concepts and designs
presented in the previous studies for this site.
This addendum has been prepared in conformance with the Fort Collins Stormwater Criteria
Manual with exceptions made for the circumstance that this project is being processed.as a minor
amendment. 1 certify that this report for the drainage design was prepared in accordance with the
Master Plan and the criteria in the City of Fort Collins Storm Drainage Manual.
I appreciate your time and consideration in reviewing this submittal. Please call if you have any
questions.
Sincerely,
Patricia Kroetch, P,E
The Summitstone Health Partners project is a Minor Amendment to the Centre for Advanced
Technology Seventh Filing which was designed and detailed in the plans and report completed by
RBD Engineering Consultants dated August 5, 1988. This site is located on Tract B of that original
plat. In the time since those plans were approved, changes have been made to the site design on
Tracts A and C which have been detailed in multiple plan sets and drainage reports and addendums
most notably, Amended Master Drainage Plan for the Centre for Advanced Technology (dated
February 1987), The Centre Avenue Residences (A replat of Tracts A and C) by Northern
Engineering dated October 13, 2009, The Arrowhead Cottages (a replat of Centre Avenue
Residences) by Northern Engineering dated August 2016, and The Centre for Advanced
Technology Fourteenth Filing. The drainage plan for this proposed project will conform to these
previously approved reports.
Historically, the majority of the site sheet flowed north and west to an existing detention pond
located in the northwest portion of the site. The proposed site will follow similar drainage patterns
as the historical drainage pattems. The majority of the site basins will be collected in the parking
lot and routed to the detention pond via pans and curb openings or direct discharge into the
detention pond as has historically occurred.
A summary of the onsite basins continue below.
Basin A is the east half of the existing parking lot. This basin is being modified slightly as 3
additional parking stalls are being added in the northeast comer of the parking lot. The runoff will
flow to a 2' curb opening as it has historically done and enter the detention pond.
Basin B is the west half of the existing parking lot. This basin is being modified slightly as the
loading area is being removed from the northwest portion of the parking lot. The runoff will be
collected in a 4' concrete on and flow north to a 2' curb opening and enter the detention pond as
it has historically done.
Basin C is the west most portion of the site which includes all of the existing building on site and
the proposed building addition. The flow patterns for this basin are around the west side of the
building and flowing north into the detention pond. This drainage pattern will be maintained with
the roof runoff from the proposed addition being collected in underground pipes and conveyed to
the detention pond.
Basin D is the undeveloped area of the site that contains the New Mercer Ditch. Runoff from this
basin enters the New Mercer Ditch and does not enter the detention pond. No changes to this basin
are proposed.
Stormwater detention is provided by an existing detention facility constructed with the Seventh
Filing of the Centre for Advanced Technology and certified with the Final Drainage and Erosion
Control Report for Centre Avenue Residences. This pond is shared with the Arrowhead Cottages
site which is adjacent to the west of this site and the CAT Filing 14 site which is northwest of the
Arrowhead Cottages. The original design for this pond included a total area of 7.81 acres which
includes Basins D2, D3 and Worthington Circle with all basins having a minor C-value of 0.71
and a major (100 year) C-value of 0.89 (0.71' 1.25). The revision to the drainage report included
with the Arrowhead Cottages development shows a composite minor C-value of 0,57 and a major
C-value of 0.72.
The Summitstone site has an existing minor C-value of 0.62 and a major C-value of 0.77. The
proposed site will have an increase of 1,753 square feet of imperviousness which will increase the
imperviousness from 48% to 50%. These values were used to compile revised composite C-values
for the 7.81 acres (Basins D2 and 133) contributing to the detention pond. The revised composite
values for the 7.81 acres area 44.4% impervious and a major c-value of 0.72. These values were
then used to recalculate the required water quality capture volume and the detention volume for
the pond. The water quality increases from 0.147 to 0.150 acre feet and the detention volume
remains the same at 1.44 acre feet which are negligible changes in the required volume for this
pond. For this reason, no increase to the existing detention pond sizing is proposed.
The proposed construction will disturb approximately 8,840 square feet which is below the
threshold of 10,000 square feet at which additional erosion control design is required.
The detention pond will be modified to accommodate the building addition as a portion of this
addition encroaches on the existing detention pond. In order to minimize the impact of this
encroachment, a small landscape wall is being proposed alongthe portion of the building that is
adjacent to the pond. The pond will also be expanded in two small areas in order to compensate
for the storage volume that is being removed for the building addition. It is anticipated that the
pond volume will remain at 1.44 acre feet at an elevation of 5046.35 NAVD 88 (elevation 5043.35
NGVD 29) as was determined in the Arrowhead Cottages drainage report. Calculations are
included at the end of this letter that show the impact of the increased imperviousness and the
modification of the existing pond. In summary, the impact of the proposed building expansion and
modifications to the site will have very minor impacts and the pond has been modified to
accommodate the encroachments.
In conclusion, this addendum has been prepared in accordance with the Fort Collins Stormwater
Criteria Manual and conforms to design completed with previous utility plans and drainage reports.
APPENDIX A
DRAINAGE PLAN & VICINITY MAP
PROJE
LOCATI
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APPENDIX B
HYDROLOGY CALCULATIONS
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APPENDIX C
DETENTION POND MODIFICATIONS
MODIFIED DETENTION VOLUME REQUIRED
FAA METHOD
(BASINS D2& D3,100-YEAR)
LOCATION:
Summitstone Health Partners
PROJECT NO:
378-01
COMPUTATIONS BY:
PPK
SUBMITTED BY:
North Star Design, Inc.
DATE:
4/30/2018
Equations:
Qo = CiA
V, = T*CiA = T*Qo
Vo=K*Qro*T
S=V, -Vo
Rainfall intensity from City of Fort Collins IDF Curve
A trib. To pond =
7.81
acre
CIM =
0.72
** see below
Developed C*A =
5.6
acre
Q� =
1.4
cfs
K=
I
(from fig 2.l)
Storm
Duration, T
(min)
Rainfall
Intensity, i
(in/hr)
Qo
(cfs)
Vol. In
V;
(ft)
Vol. Out
V*
(fe)
.Storage
S
W)
Storage
S
(ae-ft)
5
9.95,
56.0
16785
420
16365
0.376
10
7.72
43.4
26047
840
25207
0.579
20._ _
_ 5.60
_ _ _ 31.5
37788
1680
36108
0.829
30
4.52
25.4. _
45750
2520, _
43230_
0.992
40
3.74
21.0
30474
3360
47114
1.082
50
3.23
18.2
54489
4200
50289--
1.154
60
2.86
16.1
57896
5040
52856
1.213
70
2.62
14.7
61878
5880
55998
1.286
80
2.38
13.4
64239
6720
57519
1.320
90
2.22
12.5
67411
7560
59851
1.374
100
_.2.05_
_ 11.5,
69165_
8400_ _
_ 60765
1.395..
110
1.93
10.9._ ..
7.1628. _
9240 _
62388__.
_ 1.432 _
-- 120 _
- 1.80
.. -.10.1.
_72877
.10080_ -
62797
---- 1.442.--
130
1.60
9.0
70178
10920
59258 _
1.360
140
- 1.40 -
---- - -- 7.9
66129
11760 -
- 54369 -_..
- - 1.248 -
150
1.20
6.7
60731
12600
48131
1.105
160
1.15
6.5
62080
13440
48640
1.117
170
1.10
6.2
63092
14280
48812
1.121
180
1.05
5.9
63767
15120
48647
1.117
Required Storage Voiatne: 62797 ft3
1.442 acre-ft
* * 0.5 acres at 0.77 + 6.31 acres at 0.71) / 7.81 acres = 0.72
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STAGE -STORAGE TABLE
(100-YEAR)
LOCATION:
Summitstone Health Partners
PROJECT NO:
378-01
CALCSBY:
PPK
SUBMITTED BY:
North Star Design, Inc.
DATE:
4/20/2018
EXISTING POND
WQC Volume Required = 0.147
100 yr Detention Volume Required = 1.446
(On NGVD 1929 datum)
Stage
(0)
Surface
Area
(ft)
Incremental
Storage
(ac-ft)
Total
Storage
(ac-ft)
5039.20
645.33
5039.40
2450.42
0.007
0:007
5039.60
5291.24
0.017
0.024
5039.80
7639.85
0.030
0.054
5040.00
9359.05
0.039
0.093
5040.20,
10856.29_
- 0.046_-
- 0.139
5040.23
11008.61
0.008
0.147-
5040.40
11808.30
0.052 "
0--191-
5040.60
12559.23
0.056
0.247
5040.80
13148.15
0.059
0.306
5041.00
14013.52
0.062
0.368
_5041.20_
14680.01_
0.066
0.434
5041.40
15433.82
0.069
0.503 _
- 5041.60
16171.07- "
'0.073
0.576
5041.86
17156.13
0.076
0.652
5042.00
18654.88
0.082
0:734
5042.20
20134.80
0.089
0.823
5042.40
21217.82
0.095
0.918
5042.60
_22292.83
0.100_
_1.018_-
5042.90
23490:37
0.105
L123
5043.00
24775.61
0.111
1.234
5043.20
26171.89
0,117
1.35.1_
5043.35
-27239:15
-0,094
1.445
5043.40
27557.94
0.123
1.474
<==WQCV
<=100 yr HWEL
MODIFIED POND
WQC'Volume Required = 0.149
100 yr Detention Volume Required = 1.442
(On NAVD 1988 datum)
To convert from 1929 datum, add 3.18'
Stage
(ft)
Surface
Area
(ft2)
ncremenfa
Storage
(ac-ft)
Total
Storage
(ac-ft)
-5042.38
- 645.33
-
5042.58
2450.42
0:007
0.007"
5042.78
5291.24
0.017
0.024
5042.98
7639.85
0.030
0.054
5043.18
9359.05
9.039
0.093
5043.38
10856.29
0.046
0.139
5043.42.
11046.69
0.010
0.149_
-5043.58
11808.30-
0.052
0.191-
5043.78
12559.23
0.056 -
- -0.247
5043.98
13148.15
0.059
0.306
5044.18
14013.52
0.062
0.368
5044.38
14680.01
1 0.066
0.434
5044.58
15433.82 _
0.069
0.503
_5044.78.
16171.07
_0.073 _.
_._ 0.576_ _
-5044.98
17156.13 _
-0.076
0.652
5045.18
18654.88
0'.082
0.734
5045.38
20134.80
0.089
0.823
5045.58
21217.82
0.095
0.918
5045.78_
22292.83
0.100 _
1.018
5045:98 '
- 23703.95 -
' 0.106 `
, ' " 1.124 "
5046:18-
-24861.31
-0,111-
.,5046 38
.26018 68 _.
_ 0 117
1352_,____
_5046.53-
26909.85_-
0094'
._._1.446_:_.
75046:58--
'"27176:04`
0 122 ''
E474
Modified values
(due to ret Wall) have
been shaded
<==WQCV
<=100 yr HWEL
Final Drainage and Erosion Control Report
for
Centre Avenue Residences
(Being a Re -plat of Tract A and Tract C, Centre for Advanced Technology P.U. , Sep nth Filing)
Fort Collins, Colog6b of Ft Celli Hans
Approved By
Prepared for:
Mr. Stan Everitt
Everitt Companies
3003 East Harmony Road, Suite 400
Fort Collins, Colorado 80528
Prepared by:
NORTHERN
ENGINEERING
200 Sautn C011W avenue. Suar 100
F.O. Cdh.. Cdarew 8=4
PM 970.2214158 Fo: 970.221.4159
.na h"M*neniip.
Project Number: 110-034
s unofficial copy was downloaded on Sep-13-2017 from the City of Fort Collins Public Records Website: http://citydms.fegov.wm
additional information or an official coov. olease contact Ciry of Fort Collins Utilities 700 Wood Street Fort Collins. CO 90524 US
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APPENDIX B
Detention and Water Quality Calculations
unofficial copy was downloaded on Sep-t3-2017 from the City of Fort Collins Public Records Website* http://cirydocs.fcgov,wm
additional in formal ion or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins. CO 80524 US
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APPENDIX D
EROSION CONTROL SURETY
Erosion and Sediment Control Escrow/Security Calculation
for The City of Fort Collins
Project: SUMMITSTONE HEALTH PARTNERS Disturbed Acres: 0.21
BMP Amount
_ _
Estimated
Unit
Total
EROSION CONTROL BMPs
Units
Quantity
Price
Price
Silt Fence
L.F.
302
$3.00
$906.00
Rock Sock
each
6
$85.00
$510.00
Rock Berm
each
0
$220.00
$0.00
Vehicle Tracking Control Pad
each
1
$1,500.00
$1,500.60
Concrete Washout
each
1
$1,200.00
$1,200-00
Inlet Protection
each
0
$210.00
$0.00
Sub -Total: $4;116.00
1.5 x Sub -Total: $6il74.00
Amount of security. $0,174.00
ReseedingAmnunt
Total Acres x Price/acre: $252.00
Unit Price of Seeding per acre: $1,200.00 Sub -Total: $252.00
1.5 x Sub -Total: $378.00
Amount to Re -seed. $378.00
Miriiumuin Fscrow Amount
Minimum escrow amount. $3,000.00
Erosion Control Escrow.
"The amount ofthe securitymust be based on one and one-halfdmes the estlmme ofthe cosl to instal( the approvedmeasures, or one and one-ha(fdmes
the cost to re-vegetme the disturbed land to dry land grasses based upon unit cost determined by the City Annual Aevegetation andStobl/izadon Bid,
whichever is greater. /n no instance, will the amount ofsecurily be (ess than one thousand flue hundred dollars (S/,500) for residentialdevelopment or three
thousand dollars (53,000) for commerclal development"
10/2k017 3:54 PM N:W&41 Summ Slone runnpe�ovenEs Xis
APPENDIX E
EROSION & SEDIMENT CONTROL REPORT
EROSION & SEDIMENT CONTROLS
1.0 Written Analysis
An Erosion and Sediment Control Plan is included herewith. It should be noted, however,
that any such Erosion and Sediment Control Plan serves only as a general guide to the
Contractor. Staging and/or phasing of the BMPs depicted, and additional or different BMPs
from those included may be necessary during construction, or as required by the authorities
having jurisdiction.
It shall be the responsibility of the Contractor to ensure erosion control measures are
properly maintained and followed. The Erosion and Sediment Control Plan is intended to
be a living document, constantly adapting to site conditions and needs. The Contractor shall
update the location of BMPs as they are installed, removed or modified, in conjunction with
construction activities. It is imperative to appropriately reflect the current site conditions
at all times.
The Erosion and Sediment Control Plan shall address both temporary measures to be
implemented during construction, as well as permanent erosion control protection. Best
Management Practices from the Volume 3, Chapter 7 - Construction BMPs will be utilized.
Measures may include, but are not limited to, silt fencing along the disturbed perimeter,
gutter protection in the adjacent roadways and inlet protection at proposed storm inlets.
Vehicle tracking control pads; spill containment and clean-up procedures, designated
concrete washout areas, dumpsters, and job site restrooms shall also be provided by the
Contractor.
Grading and Erosion Control Notes can be found on Sheet 2 of the Utility Plans. In addition
to this report and the plan sheets, the Contractor shall be aware of and adhere to the
applicable requirements outlined all Development Agreements pertaining to this property.
Also, the Site Contractor for this project will be required to secure a Stormwater
Construction General Permit from the Colorado Department of Public Health and
Environment (CDPHE), Water Quality Control Division - Stormwater Program, before
commencing any earth disturbing activities. The Contractor shall also develop a
comprehensive Storm Water Management Plan (SWMP) conforming to applicable
requirements including descriptions of the ongoing activities, inspections and maintenance
of construction BMPs.
The site is approximately 1.50 acres and approximately 9300 square feet of which will
undergo earthmoving operations.. The existing site has an existing building, parking lot and
landscaping cover approximately 75% of the site and an irrigation ditch that covers
approximately 20% of the site.
Runoff from this site currently discharges into an existing detention pond and the
improvements will continue this runoff pattern.
The soils on this site are classified by the USGS Soil Survey as Nunn Clay Loam and are
classified in the hydrologic group C. These soils are characterized as having a slow
infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that
impedes the downward movement of water or soils of moderately fine texture or fine
texture. These soils have a slow rate of water transmission. The rainfall erodibility is
deemed to be moderate and the wind erodibility is deemed to be moderate to high.
The site is surrounded by developed sites including streets, buildings and paved areas. The
construction.shall utilize silt fence around the perimeter to control sediment transport from
rainfall and from wind. The silt fence that is located in the proposed pavement areas will
be removed prior to placing new pavement. Rock socks will be utilized in the existing curb
and detention pond to capture sediments that are not fully contained by the silt fence
placement. The locations of the rock socks will be in the areas of concentrated flow such
as in the existing curb and on the concrete pans.
The site will also utilize a vehicle tracking control pad to minimize sediment from being
tracked onto adjacent pavements. Sediment that is tracked will be removed and placed
within the site or permanently disposed of offsite. A concrete washout will be used on site
during the concrete placement. All hardened concrete will be disposed of offsite. These
BMP's have not been located on the site map due to the fact that the site is very small and
these BMP's will need to be placed by the contractor in locations that are most beneficial
and will minimize disruption of adjacent traffic.
Permanent erosion control consists of covering the soils with a building, concrete walks,
concrete pavement, recycled asphalt pavement and sod. No soil will be left exposed to
erosion after the construction is complete. Refer to the landscape plan for areas of and
instructions for placement of sod and soil amendments required prior to placement of sod.
Refer to Appendix D for the Erosion Control Surety calculations.
10 SWAP contact information
Permit holder:
Name:
Address:
Phone Number:.
Email Address:
Appointed agent:
Name:
Address:
Phone Number:
Email Address:
3.0 Identification and location of all potential pollution sources
Potential Pollutant Source Activity
- -
Potential Pollutant
Generated
Applicable to
this project
- Control'Measdre
Disturbed Areas
Sediment
X
Silt Fence, Rock Socks
Soil stockpiles
Sediment
X
Silt Fence, Rock Socks
Travel to adjacent public streets
Tracked sediment
X
Tracking Pad, street sweeping
Contaminated soils
Sediment, chemicals
Possible
Remove contaminated soils
from site **
--
Loading and unloading chemicals
Chemicals
Unloading of building materials
Trash, debris
X
Trash dumpsters, Waste
Management Finn
Outdoorstorage of chemicals
Chemicals
On site equipment maintenance
Oil, grease
On site equipment fueling
Diesel, gasoline
X
Containment berm **
Dust generating activities -
Particulates, sediment
X
Water truck
Ute of fertilizer, pesticides, herbicides
Fertilizer, pesticides
Use of detergents, solvents, oils
Detergents, solvents, oil
X
If spilled, remove
contaminatedsoils from site
Waste dumpst irs, waste piles
Chemicals, trash, debris
X
Waste Management Firm
Concrete washout
-- - - —
Concrete, sediment, wash
water
X
Remove hardened concrete,
dispose of offsite **
On sitee_4uipment washing
Detergents, oil
On site asphalt batch plant
Asphaltic cement, sediment
On site concrete batch plant
Cement, sediment
Portable toilets
Domestic sewage
X
Waste Management Finn
** Refer to Section 1.5.2 for additional Materials Handling & Spill Prevention BMP
4.0 Best Management Practices (BMP's) for Storrriwater Pollution Prevention
Structural Practices for Erosion and Sediment Control
Structural practices for the site will consist mainly of silt fence and rock sock filters and
are described in detail in the following paragraphs. These BMP's are expected to change as
the construction progresses and it is the responsibility of the contractor to ensure
appropriate BMP's are in place and/or removed at the appropriate time in the construction
sequence. All temporary and permanent erosion and sediment control practices must be
maintained and repaired as needed to assure continued performance of their intended
function.
Silt fence and rock sock filters shall be in place prior to commencement of construction
activities. During clearing and grubbing necessary for silt fence installation, all cleared
material shall be placed on the uphill side so that if erosion occurs from the cleared
material, the sediment will be trapped and not transported downstream. Rock socks shall
be implemented in the existing curb line as shown on the Drainage & Erosion Control Plan.
All BMP'sshall be installed per the details shown on the construction plan set.
Temporary & Permanent Structural BMP's:
Structural BMP .
Approximate locanon onsita •
Applicable io,this
Project
Silt Fence
Site: perimeter, refer to site map -
X
Straw bale dims
Rock Socks
At existing sidewalk culverts, in existing
gutters, refer to site map
X
Earthen diversion dain5
Vegetated swales
Sediment trap/pond
Pipe slope drains
Geogrid
Inlet/outlet protection
In the detention Pond
X
Culverts
Refer to site map
-
- - X
Riprap
- -
Erosion control mats
Inlet protection
Vehicle Tracking Control. Pad,
At site entrance, refer to site map
X
Concrete Washout -
To be located -by Contractor
X
Non -Structural Practices for Erosion and Sediment Control:
Soils exposed during the earthwork phase and landscape prep phase shall be kept in a
roughened condition by ripping or disking along land contours until mulch, vegetation, or
other permanent erosion control is installed. No large amount of soils (in excess of 15
yards) will be allowed to be stock piled on site. Overburden from the utility pipe trenching
will be piled adjacent to trenches upstream of sediment controls and will be replaced in the
trenches within 72 hours.
Excess excavated materials from the demolition and grading phases of the project that
cannot be reused on site will be exported as it is excavated. This includes any asphalt
pavement fromthe existing site that is to be removed.
A vehicle tracking pad will be installed at a location mostbeneficial to the site construction
as determined by the contractor. Vehicles will not be permitted in the excavated area if
soil is muddy. Gravel sub base will be placed and compacted in the areas indicated for
pavement following excavation. In the current pre construction state. the site enables
tracking of silt onto the adjacent streets during wet conditions. During construction
activities the street will be monitored for foreign debris tracked out of the site and
mechanical sweeping and clean up will be performed as needed.
No area shall remain exposed by land disturbing activity for more than thirty (30) days
before required temporary or permanent erosion control (e.g. seed/mulch, landscaping,
etc.) is installed.
Temporary & Permanent non-structural BMP's:
Non -Structural BMP
Approximate location on site
pplicable tot A ' his -
Proiecf
Surface roughening
Soil stockpile height limit (less than
- -
10' )
Perimeter vegetative buffer
All boundaries of:site
X
Minimization of site disturbance
-
Mulcfi
Seed & mulch -.stockpiles after 30
days
Stockpile toe protection (silt fence; —
wattles or ditch)
Preservation & protection of existing
All boundaries of site
X
vegetation & trees
Good site housekeeping (routine
Entire Site
X
cleanup of trash & cwnstr debris)
Sweeping & scraping of hardscape
On and off site pavements
X
areas
Heavy equip staged on site, properly
--
maintained & inspected daily (no
Staging area
X
onsite maintenance)
5.OBMP Implementation
5.1 Phased BMP Implementation
BMP's are expected to change as the construction progresses and it is the responsibility of
the contractor to ensure appropriate BMP's are in place and/or removed at the appropriate
time in the construction sequence. A. construction sequence schedule has been included on
the Drainage & Erosion Control Plan and included in the construction plans for this site.
All BMP's shall be inspected and repaired or replaced as required to satisfy the conditions
of the Stormwater Discharge Permit. All BMP's must be maintained and repaired as
needed to assure continued performance of their intended function. Refer to Appendix E
for the BMP schedule and estimated costs.
5.2 Materials Handling and Spill Prevention:
Materials Handling & Spill Prevention BMP
Approximate location on site
Appl'cable to "
this Project
Portable toilets, anchored & located away from
Contractor to determine
X
drainages
- -
Fuel, storage located -in bulk tanks with secondary--
-
containment & spill. kit
Mobile fueling performed at least 200 feet away from
Contractor to determine
X
drainages & fully attended
- -
Fertilizers, foim oil, solvents, cleaners, deetergenf
- -
-
stored in,55'gal or smaller containers, kept in storage
Contractor to determine
X
units
Dumpsters containing used chemicals containers &
Contractor to determine
X
liquid wastes kept covered
Equipment cleaning (on site) uses no detergents &
flows to onsite,retention basin
In case of a release of fuel or other chemicals,
absorbent booms or earthen berms will be
Location of spill
X
immediately cdnstritcted to contain the spill &
prevent runoff to adjacent surface waters
MSDS sheets for onsite chemicals will be kept at the
-
construction trailer to facilitate spill response &
Contractor to determine
X
cleanup
5.3 Dedicated Asphalt or Concrete Batch Plant:
Not proposed with this development
5.4 Vehicle Tracking Pad:
Vehicle tracking control pad shall be installed wherever construction vehicle access
routes intersect paved public roads. Vehicle tracking control pads shall be installed to
minimize the transport of sediment (mud) by runoff or vehicles tracking onto the paved
surface. Any mud tracked to public roads shall be removed on a daily basis and after any
significant storm that causes sediment to be transported. It is unlawful to track
sediment/mud onto public streets and may be enforced by the City of Fort Collins, by the
State of Colorado or by the EPA.
5.5 Waste Management and Disposal:
Portable toilets will be 'anchored & periodically maintained by waste management
company. Dumpsters on site will be covered & periodically emptied by waste management
company. Concrete waste will be allowed to harden and then will be removed from site.
No washing activities will occur on site.
Location of the concrete washout is shown on the site map. The washout will be sufficiently
deep to accommodate all anticipated concrete truck wash water. Waste concrete will be
allowed to harden and be removed from site periodically as the Washout reaches 50% of its
capacity. Truck wash water will not be allowed to reach the curb & gutter or any other
water course.
5.6 Groundwater and. Stormwater Dewatering:
No groundwater was encountered during soils exploration therefore ground water is not
anticipated to be an issue. If groundwater is encountered a groundwater discharge permit
shall be obtained and a detailed report shall be completed describing the location and the
route of where pumped groundwater will be conveyed and the measures taken to prevent
the transport of any pollutants to downstream waters.
5.7 Inspection & Maintenance:
It is required that routine site inspections are performed to effectively address maintenance
and repair of Best Management Practices (BMP's). The site inspections are to performed
by the contractor or an inspector designated by the administrator at a minimum of once
every fourteen (14) calendar days on active construction sites and after any significant
storm event (an event causing runoff). As part of the site inspections the inspector is
required to keep documentation of all inspections and BMP maintenance, including an
updated Site Map indicating new BMP's or the removal of BMP's since the previous
inspection.
Any maintenance, repair, or necessary installation of BMP's that are noted during the
inspection must be completed within seven (7) calendar days from the date of the
inspection.