NC0023884_Technical Correction_20191107

Scheller, Roberto
From: Robert Loper <[e-mail]> AeC#1V96NC0ENR/DWR
Sent: Thursday, November 7, 2019 11:48 AM NOV Q 7 'C19
To: Scheller, Roberto
Subject: [External] September WOROS
MOORESVILLE RECIONAL OFFICE
Mr. Roberto Scheller,
YE had a pH violation of 5.92 on Monday, September 23, 2019. The violation was discovered 9/27/2019, 1 called in the
violation to Andrew Pitner, DEQ/DWR/MRO, 9/27/2019 at 3:42 pm.
Below is a summary of the pH investigation
On Tuesday, September 241h, 2019 around 1230 Brian Waller SPO noticed that the GE pH sample was a 5.85 at 0800 and
5.97 at 1200. He had the operator pull another GE sample while he calibrated the backup meter. He compared the two
meters at that time and our Hach meter read 5.97 compared to our VWR meter at 6.97. At that time, he replaced the
probe on our Hach meter. He attempted to perform the calibrations, but the meter would not calibrate. At that time,
he put the VWR, spare meter in service. On Wednesday, September 25t^, Brian contacted Hach technical support, and
we were able to get the new probe working. We ran tests on the original probe, however, they determined that the
probe was not in range on the millivolt scale. The probe would not read a sample, continued to stay out of range. The
technician had him reinstall the new probe, he had Andrew Moysan run the calibration and everything ran through with
correct calibration. He then spoke with Toni, our Hach sales representative, and she is going to replace the bad probe
for us.
Thank You
Robert (Bob) Loper
WWTP Operations/ Bio-Solids Supervisor-ORC
Salisbury -Rowan Utilities I I Waste Water Treatment Plants Bio-Solids Program
1915 Grubb Ferry Rd. Salisbury, North Carolina, 28144
Ph: [phone] Cell: [phone]