NCG030716_Tier III Action Plan_20221230

RED HEAD @ Bdift PTA
This Action Plan is in response to the required Tier Three Response under General Permit NCG03000 Certificate of
Coverage NCG030716 for the PNA Construction Technologies facility located at 2027 Gateway Boulevard in Charlotte,
North Carolina.
Documentation of Benchmark Exceedances
There have been four stormwater benchmark exceedances for copper under the permit term starting July 1, 2021. These
exceedances occurred on the October 28, 2021; February 23, 2022; March 31, 2022; and November 15, 2022 sampling
events. See Table 1 below for the sample dates and the analytical results from these events.
Table 1: Benchmark Exceedances
Sample Date
Parameter in Excess of Benchmark
Analytical Result (mg/L)
October 28, 2021
Copper
0.0137
February 23, 2022
Copper
0.0133
March 31, 2022
Copper
0.0283
November 15, 2022
Copper
0.0146
The General Permit benchmark concentration for copper is 0.010 mg/L.
Stormwater Management Inspection and Potential Source Identification
Plant manager Randy Riffle and a WSP employee performed an industrial activities inspection on December 12, 2022.
The industrial activities at this site include bending, forming, cutting, and welding of steel plates, wire, and flat bar for the
manufacture of reinforcing steel for use in reinforced concrete construction. The PNA facility has an air pollution control
system consisting of dust collectors and storage of metal dust collected, outdoor oxygen and water tanks, loading dock for
shipping materials, outdoor unloading area for receiving raw materials, and outdoor staging of raw steel, finished steel
products, and wooden pallets.
Raw steel materials are delivered by truck and unloaded and stored on wood pallets in gravel and grassed
areas in the southern portion of the site, south of the site building. The materials are then transported into the
building for bending, welding, and coating activities. In addition to raw steel, the facility also receives new wood
pallets that are used for storage of finished steel materials. These new wooden pallets are delivered by truck
and stored outdoors. Raw oils and coatings materials are delivered to the facility in drums and are stored
indoors for use.
Intermediate products, byproducts, and wastes generated at the facility during the manufacture of finished
products include solid wastes, used oils, metal dust, and new and used propane tanks. Because production
activities are conducted indoors, intermediate products are not generally exposed to stormwater. However, the
dust collector and dust storage for the cutting process are exterior to the building. The dust is collected in 55-
gallon drums that are stored along the exterior of the facility in the vicinity of the dust collector units to the
northeast of the facility.
The exterior dust collector system was identified as a potential source of the elevated copper concentration in
the stormwater as a result of Tier I and II inspections and additional site sampling. As a result, an approximate
4000-square foot area was cleaned on June 8, 2022. Then, according to plant personnel, dry sweeping took
place around the dust collection area on a daily basis when full drums were removed, and empty drums put
into service.
155 Harlem Ave, Glenview, IL 60025
www.itw-redhead.com • www.ramset.com • www.itwbuildex.com • www.pna-inc.com

--U RED HEAD Bdift P
During the December 12, 2022 inspection, metal dust was observed in the area of the dust collectors in an
area exposed to stormwater. The majority of the dust is composed of iron; however according to the safety
data sheet for the material being processed, the material contains up to 0.9% copper. The dust also contains
copper from the consumed copper plasma torch tips.
Standard Operating Procedures
Dust Collector
It was identified that when a filter fails in the dust collector system, employees are not immediately aware that
the filter has failed until dust is observed discharging from the system to areas that are exposed to stormwater.
Additionally, it was identified that during drum changes, which can occur one to two times per shift, small
amounts of dust may be spilled onto the ground in an area exposed to stormwater. The current process for
cleaning the spilled dust is to sweep it up; however, this process may not always recover all of the spillage.
Source and Operational Controls/Improvements to Reduce the Identified Sources
As a result of observing metal dust around the dust collector, the following actions are proposed to reduce
stormwater impacts.
Dust Collection Efficiency Improvements
PNA Construction will evaluate the feasibility of installing an alarm that will notify the equipment operators that
a filter is not functioning and needs replacement. Additionally, the preventative maintenance plan for the dust
collectors will be reviewed to increase the filter replacement schedule.
The feasibility of installing an alarm on the dust collector system will be completed by January 15, 2023. If
feasible an alarm will be installed within two months of this determination.
Cleaning Procedure Improvements
Cleaning with an industrial floor sweeper will take place in the area surrounding the dust collector, to remove
loose dust that is currently exposed to stormwater. Additionally, a new cleaning procedure will be implemented
each time that a drum is changed. This procedure will require the use of a vacuum as opposed to sweeping the
area. The cleaning will include incidental dust spilled during the drum change process, and will also include a
weekly general area cleaning.
The new procedures for routine cleaning at the dust collector will be implemented by January 15, 2023.
Monitoring
Monitoring of Outfall 001 will continue on a monthly basis until copper concentrations are below the benchmark
for three consecutive samples. Select additional `investigative' sheet flow and grab samples will be obtained
from the locations shown in Figure 1 both prior to and after the above -described new cleaning procedure in an
attempt to determine the effectiveness of the cleaning. The sheet flow and grab samples will be analyzed for
total copper which is the only parameter that is above a benchmark.
155 Harlem Ave, Glenview, IL 60025
www.itw-redhead.com • www.ramset.com • www.itwbuildex.com • www.pna-inc.com

--to RED HEAD' @ Ramset. 1 k rr BuildPJc P
F
Fiaure 1- Aaaroximate `Investiaative' Sam de Locations
_r a Outfall
La dWdt/ Total Area Impervious Impervious
LOlglt & (acres( Area (noes) percentage '%
35.24376-/ -
80.90632'
7 _ r-
i a .. `
r
`1.
s�
Sheet Flow Sample
Grab Sample 7
155 Harlem Ave, Glenview, IL 60025
www.itw-redhead.com • www.ramset.com • www.itwbuildex.com • www.pna-inc.com