HomeMy WebLinkAboutNC0089885_More Information (Received)_20190918
P R O F E S S I O N A L | P R A C T I C A L | P R O V E N
5401 Reagan Drive, Suite 8 , Charlotte, North Carolina 28202
t. 980.321 .4100 / f. 980 .321 .4099 / usanova.com
July 8, 2019
NCDENR – DIVISION OF WATER RESOURCES – NPDES COMPLEX PERMITTING UNIT
1617 Mail Service Center
Raleigh, North Carolina 27699
Subject: Proposed Pretreatment System Summary
CHARLOTTE METRO OFFICE TOWER CONSTRUCTION
Charlotte, North Carolina
NOVA Project Number 2019008
NOVA Engineering and Environmental, Inc. (NOVA), on behalf of Childress Klein, is requesting a
NPDES permit be issued for water generated from dewatering operations during the
construction of a new high-rise office building. Once construction below the groundwater table
is completed, the collection and discharge of on-site water will be terminated.
BACKGROUND INFORMATION
The Subject Property consists of six (6) land parcels referenced by Mecklenburg Tax
Assessor’s office as Property Identification Numbers (PINs) 12505302, 12505303,
1250304, 1250306, 1250307, and 125308 with correspondi ng addresses 522 South
College Street, 518 South College Street, 510 South College Street, 509 South Tryon Street,
521 South Tryon Street, and 525 South Tryon Street, respectively. The Subject Property
encompasses a total of approximately 2.09-acres of active construction.
A previous Phase II Environmental Site Assessment performed by Anchor QEA dated April
2017 identified soil and groundwater impacts resulting from the historical use of the Subject
Property as a garment cleaning facility, an automotive sales and repair facility, and an
automotive painting facility. Petroleum impacts to soils were reported in four (4) of the nine
(9) soil borings. Chlorinated solvents above NC DEQ 2L regulations were reported in the
groundwater samples in two (2) of the five (5) groundwater monitoring wells installed.
NOVA collected groundwater samples from three (3) of the on-site monitoring wells on May
30, 2019. The remaining two (2) monitoring wells were dry at the time of NOVA’s May 2019
sample collection. The collected samples were analyzed for Volatile Organic Compounds
(VOCs) by United States Environmental Protection Agency (US EPA) Solid Waste (SW)-846
Method 8260D, Semi-Volatile Organic Compounds (SVOCs) by USEPA SW-846 Method 8270E,
Chlorinated Pesticides by USEPA SW-846 Method 8081, and Total and Dissolved Metals by
USEPA SW-846 Method 6010D and 7470A. Tetrachloroethylene (0.72-µg/L) and total
Chromium (0.029-µg/L, 0.020-µg/L, and 0.024-µg/L) were identified above NC DEQ 2L
regulatory standards. Dissolved Chromium was not detected above laboratory detection
limits.
Proposed Pretreatment System Summary July 8, 2019
South College Street and South Tryon Street NOVA Project Number 2019008
DRAFT Page 2
Based on the previously detected concentrations of chlorinated solvent and petroleum
constituent concentrations in groundwater at the Subject Property, NOVA anticipates the
required use of a pretreatment system to remediate groundwater prior to discharge to the
storm water sewer.
Summary of Proposed Groundwater Pretreatment System
The proposed groundwater pretreatment system consists of an 18,500-gallon weir tank to
settle large gross solids (50 microns and larger). The water would then be pumped through
bag filters sized at 10-micron followed by bag filters sized at 0.5-micron bag filters. Finally,
the groundwater would be pumped through two (2) 1,500-pound granular activated carbon
(GAC) filter vessels. NOVA anticipates the GAC vessels will remove the detected chlorinated
solvent and petroleum constituent concentrations. This system has an approximate capacity
of up to 100 gallons per minute.
If you have any questions, or if we may be of further assistance, please do not hesitate to contact
us.
Sincerely,
NOVA Engineering and Environmental, LLC
Keith Rice Nickolaus DaSantos
Senior Geologist Business Unit Manager
Environmental Services
Attachments: Component Specification Sheets
Steel Tank
Overview:
Features:
Specs:
Store liquids with confidence with Rain for Rent’s
18,100-gallon Open-Top Wier Tank. The over and under
weirs allow for separation of oils or particulates. Permanently
attached axles, for maximum maneuverability, allows this tank
to be moved with ease on the jobsite. The staircase ensures
proper protection for workers on site. The tank also offers
optional epoxy coating, which offers chemical resistance and
additional cleanliness for sensitive environmental applications.
• V-drain floor with front and rear 4” 150-lb flanges with valves
• OSHA Compliant Stairway
• Rear 4” or 6” SCH40 fill line**
• Rear 4” or 6” skimmer port**
• Each tank has 2 or 4 weirs per tank, which are up to 8.5ft
wide**
• Optional: Epoxy Coating - chemical resistance for a wide
variety of chemical compatibility and keeps stored product
within the tank cleaner
Open-Top Weir
Accessories:
• E-CONTAIN® Spillguard
• SolidGroud® Traction Mats
• Radar Level Gauges
• Mechanial Level Gauge
• PipeStax®
• HoseTrax®
• Suction and Discharge Hose
Material Steel, Epoxy Coated
(Option)
Capacity 18,100 gallons
Manways Three 22” hatches
Dry weight 27,000 lbs.
Footprint: 516” x 102” x 126” 800-742-7246 rainforrent.com
PUMPS • TANKS • FILTRATION • PIPE • SPILLGUARDS
Rain for Rent is a registered trademark of Western Oilfields Supply Company. Features and specifications are subject to change without notice.
**Features may vary
Bag Filter
Overview:
Features:
Specs:
The BF200 bag filter unit features two bag filter tanks and
utilizes 7” x 30” bag filters for superior filtration from 100 to 1
micron for flows up to 200 GPM.
• No moving parts
• Skid mounted
• Fitted with bleed valves and pressure gauges
• Chambers constructed of 304 Stainless Steel
• Piping constructed of 304 stainless steel
• Stainless Steel inlet and outlet manifolds
BF200
Accessories:
• Spillguard
• Suction and Discharge HosesMax Flow 200 GPM
Material Stainless Steel
Max PSI 125 PSI
Dry weight 800 lbs.
Footprint: 48” x 36”
Inlet x outlet 3” x 3” Flange
800-742-7246 rainforrent.com
PumPs • Tanks • FilTraTion • PiPe • sPillguards
Rain for Rent is a registered trademark of Western Oilfields Supply Company. Features and specifications are subject to change without notice.
●Welded Steel Construcon
● Mul-Coated Corrosion Resistant Epoxy Interior
□ Flow Instrumentaon
□ Flexible Interconnecng Hose
□ Complete line of granular acvated carbon and other media