20090566 Ver 3_O&M Agreement Modification Request_20170202

January 30, 2017
401 Oversight/Express Review Permitting Unit
Division of Water Resources
Department of Environmental Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Approved O&M Agreement Modification
Caterpillar Clayton Machine Development Center
Caterpillar Access Road
Johnston County
DWQ Project # 09-0566
Amec Foster Wheeler Project No. 6480166087
Dear 401 Oversight/Express Review Permitting Unit,
Amec Foster Wheeler Environment & Infrastructure, Inc. (Amec Foster Wheeler) on behalf of
Caterpillar Clayton Machine Development Center would like to request a revision to the
approved O&M Agreement part of their Stormwater Management Plan Approval dated
November 16, 2010. The attached O&M Agreement includes minor edits to formatting and
removes the requirement to scarify or disk the entire surface of the field in a pattern
perpendicular to the natural slope (Page 3 — For the permanently disturbed areas #3).
Caterpillar has found this practice to cause more sediment transport and potential erosion than
just backfilling open holes and grading areas back to original grade per the site plans only.
If you have any questions please contact us at 919-765-9985 or brian.lowther@amecfw,com,
Sincerely,
Amec Foster Wheeler Environment & Infrastructure, Inc.
.'j
Attachments Revised Caterpillar Core PDC Test Facility Operation and
Maintenance Agreement
CC: via email Van Ellis and Jennifer Owens of Caterpillar, Inc.
Correspondence:
Amec Foster Wheeler Environment &Infrastructure, Inc,
4021 Stirrup Creek Drive, Suite 100
Durham, North Carolina 27703
Tel [phone]
Fax [phone]
Licensure: NC Engineering F-1253 AJC Geology C-247
M

CATERPILLAR i� 0 2 20
, I/ /11"�"
Caterpillar, Inc. will keep a maintenance record for the permanent stormwater devices
approved as part of the stormwater management plan for the 401 Water Quality
Certification, issued on May 21, 2009. This maintenance record will be kept in a log in a
known set location. Any deficient items noted in this inspection will be corrected, repaired
or replaced immediately. These deficiencies can affect the integrity of structures and safety
of the public.
General
Owner shall adhere to the following requirements as set forth in the approved NPDES
General Stormwater Permit NCGO1000 (Construction Activities),
�Ig 1111 IqI I ! �
i F � ]z N -19NIENVY0 M,
Minimum monitoring and reporting requirements are as follows unless otherwise
approved in writing by the Director of the Division of Water Quality.
1, All erosion and sedimentation control facilities shall be inspected by or under the
direction of the permittee at least once every seven calendar days (at least twice every seven
days for those facilities discharging to waters of the State listed on the latest EPA approved
303(4) list for construction related indicators of impairment such as turbidity or
sedimentation") and within 24 hours after any storm event of greater that 0.5 inches of rain
per 24 hour period. A rain gauge shall be maintained on the site and a record of the rainfall
amounts and dates shall be kept by the permittee. (** The latest approved list may be
obtained from the Division of Water Quality, or from the following website location:
littp.Ilh2i).eitr.st,iite.nc,.ttslstticoii,5tructioti3O3d)
2. Once land disturbance has begun on the site, stormwater runoff discharges shall be
inspected by observation for stormwater discharge characteristics as defined below at the
frequency in #1 above to evaluate the effectiveness of the pollution control facilities or
practices. If any visible sedimentation is leaving the disturbed limit-, of the site, corrective
action shall be taken immediately to control the discharge of sediments outside the
disturbed limits.
Stormwater Discharge
Monitoring Type I
Monitoring Location 2
Characteristics
Clarity
Qualitative
SDO

Floating Solids
Qualitative
SDO
Suspended Solids
Qualitative
SDO
Oil Sheen
Qualitative
SDO
Other obvious indicators of
stormwaterpollution
Qualitative
SDO
Footnotes:
No analytical testing or sainplingis.required.
2 Sample Location: Stor.mwater Discharge Outfalls) (,DO)
3. The operator shall keep a record of inspections, Visible sedimentation found outside of
the disturbed limits shall be recorded and a brief explanation kept with the records as to the
measures taken to co trio future releases, Any measures taken to clean up the sediment that
has left the disturbed lirnits shall also be recorded. These records shall be made available to
DWQ or authorized agent upon request.
If the language of the NPDES General Stormwater Permit NCGO 1000 (Construction
Activities) is updated, the owner will update this language accordingly.
Owner should contact the local NC Division of Water Quality Regional Office if there
are questions or concerns regarding turbidity or `eater quality, (Martin Richmond 919-
7�1-4250)
For the permanently disturbed areas, the owner shall provide the following Measures at
.the completion of each testing period or every 8 weeks, whichever occurs first.
1. Backfill all open holes and grade areas back, to its original grade per site plan.
2. Clean any silt from perimeter drainage ditithes around field.
Check Dams
Check da,ms shall be inspected at least once every week and within 24 hours of a
rainfall of 0.5 inches or more
If erosion has :taken place around or below the rock check dam or if rocks have
been dislodged, repairs shall be made to prevent further damage.
Sediment shall be removed once it has accumulated to one-half the height of the
rock check dam.

Erefqmjed Scour Holes
• Scour holes shall be inspected At least once every week and within 24 hours of a
rainfall of 0.5 inches or more.
• Remove any trash or debris that has accumulated in the scour hole.
• If any rip rap has been dislodged or any noticeable damage to the filter fabric has
occurred, repairs shall be made to prevent further damage.
• If any erosion has occurred on the downstream side of the scour hole, repairs
shall be made to prevent further damage.
• Sediment shall be removed once it has accumulated to one-half the depth of the:
scour hole.
Vpstrearn Vegetated Filter
• Vegetated filter shall be watered twice weekly if no rainfall occurs until newly
planted Vegetation is established. Lime and a one-time fertilizer Application may
be used.
• Vegetated filter shall be inspected quarterly or after every storm event greater
than one inch.
• Int. -noticeably eroded and bare areas, repair and reseed to establish new ground
cover.
• Vegetated filter shall be aerated and reseeded annually to maintain a dense
growth of vegetation, Additionally, pH shall be tested annually and lime added
is necessary.
• Two to three times a year, vegetation shall be mowed and the clippings
harvested to promote the growth of thick vegetation with optimum pollutant
removal efficiency. Turf ,gas's should not be cut shorter than 3 to 5 inches and
may be allowed to grow as tall as 12 inches,
• Remove any nuisance vegetation that maybe choking out desirable species.
Pen anent Sediment Skimmer Basin
• Basin should be inspected once a month and within 24 hours after every storm
event greater than 1 inch. Records of operation and maintenance should be kept
in a known set location and must be available upon request.
• Remove trash and debris if present during inspection
• In noticeably eroded and bare areas, repair and reseed to establish new ground
cover,
• Maintain vegetation at approximately 6 inches around perimeter of basin.
o lmn-tediately after the basin is established, the vegetation on all slopes should be
watered twice Weekly if needed, until the vegetation becomes established
(commonly six weeks).
o Examine inlet pipes, riser and outletpipes for structural failure and replace as
needed.

• Sediment is to be removed from the basin when it accumulates to 50% of the
basin volume or every four months. Remove the sedimentand dispose of it in a
location where it will not cause impacts to streams or the basin.
• Consult a professional to control and remove algal growth if greater than 50% of
surface area is affected,
• If cattails, phrao.ites or other invasive plants cover ,50% <of the basin surface,
remove the plants by wiping them with pesticides (do not use spray).
• No portion of the basin should be fertilized after the first initial fertilization that
is required to establish the growth on slopes.
• Keep outlet, and flow splitter device free from debris and sediment that may clog
or impeded flow.
• If the basin must be drained for an errtorgencyor to perform maintenance;
the
flushing of sediment through the, emergency drain should be,n-tinin-dzed to the
maximum extent practical.
• Annually, a geotechnical engineer should inspect the embankment.
Level Spreader
• Level Spreader shall be inspected quarterly or after every storm event greater
than one inch.
• Repair level lip if there are signs of settling, undercutting, erosion or other
damage,
• Remove trash and debris if present during inspection
• 'Remove trees, or shrubs that have grown in the level lip or in vegetated filter
downstream of level lip.
• Repair any areas,of erosion or galley formation.
Downstre jVe e" cl. Fiber
• Vegetated filter shall be watered twice weekly if no rainfall occurs until newly
planted vegetation is established, Lime and a one-time fertilizer application may
be used,
• Vegetated filter shall be inspected quarterly or after every storm event greater
than one inch,
• In noticeably eroded and bare areas, repair and reseed to establishI new ground
cover.
• Vegetated filter shall be aerated and reseeded Annually to maintain a dense
.growth.of vegetation, Additionally, pH shallbetested annually and lime added
is necessary.
• Two to three times a year, vegetation shall be mowed and the clippings
harvested to promote the growth of thick vegetation with optimum pollutant
removal efficiency. Turf grass should not be cut shorter than 3 to 5 inches and
may be allowed to grow as tall as 12 inches.
• Remove any nuisance vegetation that may be choking out desirable species,

I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify DWQ of any
problerns with the system or prior to any changes to the system or responsible party.
Project name: Caterpilla Q re CMDO'est Area
Basin ID: ALL.Scour Holes
Spreaders and Do�vnstrp x _U-MtLq Vted egetaFilters, Perniaqent Sediment Basin ,&Le�
Print name:
Title:
Address:. Phone:
Signature:
Date:
a Notary Public for the State of
County of__,,_ do hereby certify that
personally appeared before me this day of
...... and acknowledge the due execution of the forgoing pond
maintenancle requirements. Witness my hand and official seal,
SEAL
Mycommission expires ,
Mary E. Mulholland
Notary Public
Wake County, NC
(04 Gornmissign n re.q #tPr*hPr 27