NCG030010_Tier Releif Approval_20140505

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NCDENR
North Carolina Department of Environment and Natural Resources
Pat McCrory
Governor
5 May 2014
Thomas Built Buses, Inc.
Attn: Alice Wesselman, Environmental Manager
P.O. Box 2450
High Point, NC 27261
Subject: Technical Assistance Inspection & Tiered Response Requirements
NPDES General Stormwater Permit NCG030000
Certificates of Coverage NCG030009 & NCG030010
Thomas Built Buses, Inc.
Guilford County
Dear Ms. Wesselman:
John E. Skvarla, III
Secretary
Aana Taylor -Smith of the Winston-Salem Regional Office of the NC Division of Energy, Mineral, and Land
Resources (DEMLR) met with you to discuss tiered response requirements for the NCG030000 permit for metal
fabricators at the subject facility on 2 May 2014. Your assistance and cooperation were greatly appreciated.
Two Thomas Built Buses facilities were under review during this meeting. The facility covered by NCG030009 is
located at 715 West Fairfield in High Point, Guilford County, North Carolina. Stormwater related to industrial
activity is discharged from that site to an unnamed tributary to the Uwharrie River, this segment of which is
currently classified as Class WS-III Waters in the Yadkin -Pee Dee River Basin. The second facility, covered by
NCG030010, is located at 1408 Courtesy Road in High Point, Guilford County, North Carolina, and discharges
stormwater to Payne Creek, Class C Waters in the Yadkin -Pee Dee River Basin.
Documentation & Monitoring Review
This meeting was held to assess compliance with NPDES General Stormwater Permit NCG030000 and to evaluate
drainage to the facilities' Stormwater Discharge Outfalls (SDOs). Monthly monitoring has been triggered by
consecutive exceedances of the copper and zinc benchmarks at all outfalls. Please keep in mind that benchmark
exceedances are not limit violations or violations of permit conditions; however you are obligated to follow the
tiered response actions outlined in your permit. Thomas Built Buses has been following the tiered response
actions at both facilities and is therefore in compliance with the permit. Both qualitative and analytical monitoring
have been completed as required.
Site Review
The facilities are clean and well maintained. Secondary containment is implemented as required. Both sites have
the potential for stormwater to become contaminated at the outfalls due to off -site influences, including railroads
and neighboring industries. The Fairfield Road site has existing dry pond BMPs at each of the two outfalls to
mitigate stormwater contamination. SDOs may be relocated at the Courtesy Road site to attempt to avoid off -site
contamination and collect more representative samples. Please update the stormwater pollution prevention plan
(SPPP) when relocation of outfalls has been completed.
Division of Energy, Mineral, and Land Resources
Land Quality Section • Winston-Salem Regional Office
585 Waughtown Street, Winston-Salem, NC 27107 • Phone: [phone] / FAX: [phone]

Thomas Built Buses
05/05/2014
Page 2 of 2
Tiered Response Requirements
Currently, monthly monitoring is required in response to two consecutive exceedances of the benchmark values
or range for any specific parameter at a specific SDO. Thomas Built Buses has completed monthly monitoring for
all outfalls as well as taking extensive actions to identify and eliminate potential sources of pollution at both sites.
Upstream sampling and monitoring have been undertaken and housekeeping and site maintenance practices have
been reviewed and improved. Dumpsters located near outfalls have been sealed and other storage containers
have been reviewed to assess and improve their structural integrity where possible. Metals levels in the City's
drinking water have also been assessed to determine whether that could be a contributor. Blue Ridge Geological
Services has been contracted to assist with the tiered response investigation.
Thomas Built Buses has achieved ISO 14001 certification for environmental management and has taken steps to
achieve Zero Waste status. Both facilities are very well maintained. Thomas Built Buses continually takes
measures to reduce the potential for stormwater contamination on site and has a very rigorous environmental
program.
At this time, the Division concurs that more frequent monitoring at both sites would be ineffective. The Division
relieves you of the additional monitoring frequencies required in the Tiered Response section of this permit for
copper and zinc. You must continue to monitor semi-annually as required by the permit, but you will not be
required to institute monthly monitoring for any future exceedances of the copper and zinc parameters at the
SDOs for either site. Tiered response requirements still apply for all other parameters.
You must notify this office in writing within five business days if you become aware of any significant source of
copper or zinc at your facilities that has the potential to be exposed to stormwater. The relief granted in this letter
is contingent upon the current industrial practices and housekeeping actions at both Thomas Built Buses facilities.
If industrial practices change and copper and/or zinc become a significant stormwater exposure risk, this office
reserves the right to withdraw this decision and reinstate the permit -specified tiered response or other actions
that may be warranted.
We appreciate your efforts to comply with the stormwater permit and the proactive steps taken to identify and
eliminate potential sources of pollution. No additional response to this letter is required, but please append this
letter to your SPPPs to document that your facilities have been relieved of monthly monitoring requirements for
the specified parameters. Should you have any questions regarding the NCG030000 permit or this letter, please
do not hesitate to contact Ms. Taylor -Smith or me at [phone].
Sincerely,
Matthew E. Gantt, PE
Regional Engineer
Land Quality Section
cc: Ken Pickle, SPU
Central Files
WSRO/LQ