NC0045993_Meeting Notes_19940908

NPDES DOCUMENT SCANNING COVER SHEET
NC0045993
Teledyne ALLVAC WWTP
NPDES Permit:
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Meeting Notes
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
September 8, 1994
This document is printed on reuse paper - ignore any
coritent on the reYerse side

J •
NATIONAL ENVIRONMENTAI, TECHNOLOGIES, iv.
September 8, 1994
Mr. Donald L—Sfrit, P.E.
NC Department of Environment,
Health & Natural Resources
Division of Environmental Management
Water Quality Section
P.O. Box 27687
Raleigh, NC 27611-7687
SUBJECT: NPDES Permit Renewal
Teledyne Allvac - Monroe Plant
NPDES Permit No. NC 0045993
Union County
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Dear Mr. Safrit:
We appreciate the opportunity and courtesy afforded by you and your staff in meeting with us
and our client, Teledyne Allvac, on July 29, 1994. We believe it was helpful to exchange
information and ideas that should help in developing a fair and reasonable permit. In accordance
with our discussions, I have enclosed herewith the following attachments:
1. Correlation study of Teledyne Allvac's NPDES discharge vs. rainfall for the year 1993
2. Results of 7Q10 measurements for Teledyne Allvac (May 23, 1994)
3. Table summarizing discharge report data from December 1990 through January 1993
4. NPDES Compliance Inspection Report (October 28, 1987)
5. Letter from Mr. H. Curtis Gunter, USGS dated August 2, 1990
6. Letter from J. Thurman Horne, P.E. (Teledyne Allvac) to Ms. Lula Harris (NC Dept.
of EHNR) dated November 21, 1989
9400-E Southern Pine Blvd. • Charlotte. NC 28273 • [phone]/FAX [phone]

Mr. Donald L. Safrit, P.E.
September 8, 1994
Page - 2 -
7. Letter from R. Paul Wilms to Thurman Horne dated December 22, 1989
8. Letter from Thurman Horne to Carla Sanderson (NC Dept. of EHNR) dated April 9,
1991
Teledyne Allvac (Teledyne) has attempted to determine the 7Q10 flow of the receiving stream
(Richardson Creek). Unfortunately, the presence of an impoundment upstream creates an
artificial disruption of normal flow patterns and thus makes conventional stream flow assessment
methodologies inappropriate. The results of the attempts have shown that a correlation cannot
be determined since flow is greatly impacted by the release and withdrawal of water from the
impoundment. The impoundment is a water supply for the City of Monroe, therefore, release
of water from the dam, and subsequent flow downstream, is influenced by dam leakage and,
more importantly, withdrawal of water from the impoundment. The influence of these factors
on the impoundment is clearly evidenced in the inability to correlate flow in Richardson Creek
to that of the Reference USGS gauging station.
The inability to measure the 7Q10 flow of Richardson Creek returns us to the matter of
determining what is an appropriate flow to use in reissuing the NPDES Permit. The November
21, 1989 letter from Thurman Horne to Lula Harris explained the reasons the company
supported using a 7Q10 estimate of 0.32 cfs for this site. We believe that the reasons are still
valid and therefore favor reissuing the permit on this same basis and basically continuing with
generally the same effluent limitations.
We believe this is a fair and reasonable proposal especially considering that the nature of
Teledyne's discharge is such that a release clearly does not occur in low stream flow conditions.
The enclosed correlation study of Teledyne's discharge compared to rainfall shows that discharge
from the cooling pond is subjective to rain events. During periods of rainfall, discharge
increases and, conversely, in periods without rain, discharge diminishes. In extended periods
without rain, discharge from the pond cPaces. During summer months such as late May and
June, no discharge occurred despite rain events. Obviously, Teledyne does not discharge from
the cooling pond in conditions that would represent 7Q10 low flow in Richardson Creek.
During our meeting the possibility of requiring a maintained minimum release from the
impoundment was discussed. Although this would probably facilitate the issuance of the permit
we believe this would present an undue and unnecessary burden on the City of Monroe. The
City already has a shortage of available raw water supply which becomes stressed in drought
conditions. The effect would be to make the City release water it badly needs at its most critical
time. This seems unwise especially considering that, as discussed previously, Teledyne is not
discharging under the stream low flow or drought conditions.

Mr. Donald L. Safrit, P.E.
September 8, 1994
Page - 3 -
Teledyne wants a permit to be issued that is protective of the receiving stream but also that is
fair and reasonable. We believe that reissuance of the permit using the estimated 7Q10 flow of
0.32 cfs is reasonable and establishes limits which have been shown to be attainable. We believe
that the information provided supports this rationale and that this is consistent with DEM
regulations.
I hope that you will concur that this would be appropriate. If not, please let me know so that
we can discuss this further and/or discuss alternate methods which could be approved by the
Director under the discretion afforded by the regulations.
Again, my thanks to you and your staff. If you have any questions, need any additional
information or if we need to discuss, please call Mr. Thurman Horne at [phone] or me
at [phone].
Sincerely,
NATIONAL ENVIRONMENTAL TECHNOLOGIF_S, INC.
Gary C. Rlbblett, P.E.
Manager, Engineering Department
GCR/deb
Enclosures
cc: J. Thurman Horne, P.E., Teledyne Allvac