NCG080614_DMR_20230626

Semi-annual Stormwater Discharge Monitoring Report
for North Carolina Division of Water Quality General Permit No. NCG080000
Date submitted 6/26/23
CERTIFICATE OF COVERAGE NO. NCG08 0 6 1 4
FACILITY NAME Rex Oil Company
COUNTY Davidson
PERSON COLLECTING SAMPLES Ben Robinson
LABORATORY Waypoint Analytical Lab Cart. # 402
Comments on sample collection or analysis:
SAMPLE COLLECTION YEAR 2023
SAMPLE PERIOD ® Jan -June ❑ July -Dec
RECEI�✓FQ or El monthly' (month)
DI C RGING TO CLASS ❑ORW ❑HQW ❑Trout ❑PNA
JUN 3 0 2023 ❑Zero -flow ❑Water Supply [:]SA
CENTRALQOther Class C
CwR ' FILES
CTION PLEASE REMEMBER TO SIGN ON THE REVERSE 4
Did this facility perform Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month? _yes X-no
(if yes, report your analytical results in the table immediately below)
Part A: Vehicle Maintenance Areas Monitoring Requirements (If applicable)
No discharge this period'
Outfall
No.
Date
Sample Collected,
mo/dd/yr
00530
00400
00556
Total Suspended
Solids, mg/L
pH,
Standard units
Non -Polar Oil and Grease/TPH EPA
Method 1664 (SGT-HEM), mg/L
New Motor Oil Usage,
Annual average gal/mo
Benchmark
50 or 100 see permit
Within 6.0 — 9.0
15
Part B: Oil/water Separators and Secondary Containment Areas at Petroleum Bulk Stations and Terminals (If applicable)
Outfall
No.
Date
Sample Collected,
mo/dd/yr
00556
00530
00400
Non -Polar Oil and Grease/TPH EPA Method
1664 (SGT-HEM), mg/L
Total Suspended Solids,
mg/L
pH,
Standard units
Permit Limit
-
15
50 or 100 see permit
6.0 — 9.0
SDO-1
6-19-23
<3.4
27.4
7.48
For sampling periods with no discharge at any single outfall, you must still submit this discharge monitoring report with a checkmark here.
SWU-250 last revised April 11, 2013
Page I of 2

STORM EVENT CHARACTERISTICS:
Date6/19/23 (first event sampled)
Total Event Precipitation (inches): 1.01"
Date (list each additional event sampled this reporting period, and rainfall amount)
Total Event Precipitation (inches):
Note: if you report a sample value in excess of the benchmark, you must implement Tier 1, Tier 2, or Tier 3 responses. See General Permit text.
FOR PART A AND PART B MONITORING RESULTS:
• A BENCHMARK EXCEEDANCE TRIGGERS TIER 1 REQUIREMENTS. SEE PERMIT PART II SECTION B.
• 2 EXCEEDANCES IN A ROW FOR THE SAME PARAMETER AT THE SAME OUTFALL TRIGGER TIER 2 REQUIREMENTS. SEE PERMIT PART II SECTION B.
• TIER 3: HAS YOUR FACILITY HAD 4 OR MORE BENCHMARK EXCEEDENCES FOR THE SAME PARAMETER AT ANYONE OUTFALL? YES ❑ NO
IF YES, HAVE YOU CONTACTED THE DWQ REGIONAL OFFICE? YES [:]NOR]
REGIONAL OFFICE CONTACT NAME:
Mall an original and one copy of thls DMR, lncludfna all "No Discharge" reports, within 30 days of receipt of the lab results for at end of monitoring perlod In
the case of "No Discharge" reports) to:
Division of Water Quality
Attn: DWQ Central Files
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
YOU MUST SIGN THIS CERTIFICATION FOR ANY INFORMATION REPORTED:
"I certify, under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure
that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons
directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that
there are significant penalties for submitting false information, including the possibility of fines and imprisonment for knowing violations."
0
(Signature of Permittee)
6/26/23
(Date)
Additional copies of this form may be downloaded at: http://portal.ncdenr.orp/web/wcg/ws/su/npdessw#tab-4
SWU-250
last revised April 11, 2013
Page 2 of 2