NC0026441_Speculative Limits_19900205

State of North Carolina
Department of Natural Resources and Community Development
Division of Environmental Management
512 North Salisbury Street • Raleigh, North Carolina 27611
James G. Martin, Governor 6610 R. Paul Wilms
William W. Cobey, Jr., Secretary February 5, 1-989 Director
Mr. Kenny Jones
Hobbes, Upchurch 6
P.O. Box 1735
Southern Pines, NC
Associates, P.A.
28387
Subject: Proposed NPDES Permit Limits for the Siler City WWTP
Dear Mr. Jones,
This letter is to inform you of the most recent wasteload allocation for
the proposed expansion of the Siler City WWTP to 4.0 MGD. The newest change
to the proposed limits is the addition of the lead limit. As you are aware,
the loading of oxygen -consuming wastes to Loves Creek was reduced for the
expanded flow due to the downstream dissolved oxygen problems discovered
under existing flow conditions through the special studies performed by
Siler City. Limits for the toxic components of the effluent are based on
the most recent information, including a pretreatment headworks analysis and
a priority pollutant analysis. The proposed limits as of this date are as
follows:
simmer Winter
BOD5 (mg/1)
5
10
NH3 (mg/1)
1
2
DO (mg/1)
6
6
TSS (mg/1)
30
30
Fecal Coliform (4/100 ml)
200
200
pH (SU)
6-9
6-9
Oil 6 Grease (mg/1)
30
30
MBAS (mg/1)
0.5
0.5
Lead (ug/1)
26
26
Chromium (ug/1)
52
52
Cyanide (ug/1)
5.2
5.2
Mercury (ug/1)
0.012
0.012
Copper (ug/1)
Monitor
Nickel (ug/1)
Monitor
Zinc (ug/1)
Monitor
Silver (ug/1)
Monitor
Total Residual Chlorine (ug/l)*
17
17
(Daily Max.)
(Daily Max.)
(Daily Max.)
(Daily Max.)
(Daily Max.)
* Not necessary if an alternate method of disinfection
is utilized.
Pollution Prevention Pays
P.O. Bar 27687, Raleigh, North Carolina 27611-7687 Telephone [phone]
An Eaual OoDortuniw Affirmative Action ErnDlover

It is important to remember that these limits are still in draft form
and will not be finalized until an NPDES permit is issued allowing the plant
expansion. The limits may be subject to change as more information becomes
available. However, the above information should be useful for planning
purposes and for the completion of an accurate EIS.
If you have any questions or comments, please feelfreeto contact me at
[phone].
Sinc rely,
Trevor Clements, Asst. Chief
Water Quality Section
cc: Dale Overcash
Alan Clark
Arthur Mouberry, Raleigh Regional Office
Central Files

R'E VF-a'
FEB o 1 1990) '
TECH""' -'AL SUPPORT pA VCH
i�
DIVISION OF ENVIRONMENTAL MANAGEMENT p
Raleigh Regional Office S
,January 29, 1990
TO: Don Safrit, Supervisor, Permits & Engineering
THRU: `i�rthur Mouberry, PE, Regional Supervisor
1
FROM:�im Donnelly, PE, Water Quality Supervisor
SUBJECT: Siler City NPDES Permit No. NCO026441
Chatham County
The staff of the RRO has observed considerable oil & grease problems at
the subject WWTP. Accordingly, the permit should be re -opened to include oil
& grease limits with weekly sampling. Also a quarterly toxicity limit should
be added to the permit while it is being revised.
AM: TLD:ga
cc: Alan Clark
Trever Clements

DIVISION OF ENVIRONMENTAL MANAGEMENT
January 29, 1990
MEMORANDUM
TO: Alan Clark
THRU: Ruth Swanek ACS
Trevor Clements8u�
FROM: Mike Scoville MD5 (' /
SUBJECT:. Priority Pollutant Analysis for Siler City WWTP
The recent priority pollutant analysis submitted to DEM as a part of the
EIS process revealed effluent concentrations of lead, copper, and zinc that
would cause instream violations of their respective stream standards or
action levels in Loves Creek. Accounting for the dilution provided by the
Rocky River, the standard and action levels may or may not be protected
downstream in the Rocky River. The status of beryllium cannot be determined
because the detection level reported was much greater than the stream
standard. The following is a discussion of these results and their implica-
tions.
The parameter of most concern is lead. Out of the four parameters men-
tioned in your memo (beryllium, lead, copper, zinc), lead is the only one
that is bioaccumulative. Due to the high level of lead revealed by the
pollutant scan, a lead limit will be included in Siler City's NPDES permit.
The limit will be such that the stream standard (25 ug/1) will be protected
at 7Q10 conditions in Loves Creek; the lead concentration in the Rocky River
below Loves Creek will thus be lower than the standard as well.
Beryllium was reported to be less than 100 ug/l in Siler City's efflu-
ent. The stream standard for beryllium is 6.5 ug/l. Using the aspirated
atomic absorption method, the detection level of beryllium is 5 ug/l, with
optimal precision between 50 ug/l and 200 ug/l. Because beryllium is a
fairly uncommon element and the City's pretreatment headworks analysis does
not indicate a source of it, DEM has no reason to believe that it is present
in the effluent, except perhaps naturally and in very minute quantities.
Action levels exist for copper and zinc, suggesting that closer atten-
tion should be paid to these metals if their instream concentrations exceed
these levels. NCAC .0211(b)(9) describes substances for which action levels
were developed as "generally not bioaccumulative and have variable toxicity
to aquatic life because of chemical form, solubility, stream characteris-
tics, and /or associated waste characteristics." It is not known whether
copper and zinc in levels reported by Siler City will cause problems such as
accumulation in the stream sediments or impacts on benthos. It should be
noted, however, that on a relative scale, the reported effluent concentra-

tions of copper and zinc are not exceptionally high. Copper and zinc occur
naturally in substrates and in organic matter and levels much higher have
been observed without apparent detrimental effects. Also, in the analysis
procedure for total copper and total zinc, the sample is acidified to bring
everything in that sample into solution. The final total values, then,
reflect even the copper and zinc that is bound to solids and incorporated in
organic matter, and not just the dissolved species of the elements that are
reactive.
NCAC .0211(b)(4) goes on to require monitoring of any substance whose
action level is being violated instream. Effluent monitoring of copper and
zinc is required by the current Siler City NPDES permit and will continue to
be required whether the facility is expanded or not. Limits may be required
for copper and zinc "if sufficient information exists to indicate that any
of those substances may be a significant causative factor resulting in
toxicity of the effluent." Steps have been taken, through administrative
letter, to require whole -effluent toxicity monitoring by Siler City. If
effluent toxicity is reported, the City will be required to determine its
source and take corrective action, and effluent limits may be imposed at
that time.
There is no doubt that Glendale Hosiery Mill is a source of copper and
zinc. Siler City's pretreatment program exists to provide control of pollu-
tant loading rates to the WWTP from significant industrial users. As a part
of this program, Glendale has it's own effluent limits and monitoring
requirements and a legal obligation to comply with them. If their monitor-
ing data show that they are in violation of their limits, the City is
required to take enforcement action against them; if the City takes no
action, DEM is required to take enforcement action against the City.
If you have any further questions, please feel free to contact me.
cc: Dale Overcash

TO:
FROM
SUBJECT
I
DIVISION OF ENVIRONMENTAL MANAGEMENT
January 19, 1990
Trevor Clements
IV�y Fr
ED
AN 2 2 1990
a TECHh"W„ L 1U1P' 0P,-I BRAtdCH
Alan Clark /IT
Priority Pollutant Scan for Siler City WWTP
EIS
Connie Allred of the Friends of Rocky River (FORR) was
provided with a copy of the priority pollutant scan that you had
requested last September and has brought to my attention the fact
that at least four of measured parameters exceed (or may
exceed in the case of Beryllium) stream standards. This is a
concern to FORR because during low flow conditions, the plant
effluent makes up most of the stream flow.
Measured levels (ug/1)
Parameter Influent Effluent Standard (ug/1)
Copper 60
Beryllium L 100
Lead 30
Zinc 120
(AL) = Action Level
(N) = Narrative Level
20
s"�j1 7
(AL)
L 100
,.� 6.5
(N)
30
ae '` 40^ 25
(N)
80
^ s^'Q 50
(AL)
Hf1'\ oel. ' DCL6.
;JIB
L = Less
than
41 t� s0 . 2 o,
As presented above, two of the parameters exceed established
action levels. According to our rules (02B .0122(b)(4)),
monitoring and other possible actions may be required when action
levels are exceeded. What if any action should be taken in
regard to zinc and copper? FORR is concerned that if these
concentrations stay constant as the plant effluent increases,
then the total loading to the stream would increase. Are there
long term problems associated with high levels of these
substances such as accumulation in the stream sediments and
impacts to benthos? FORR also points out that the Glendale
Hosiery Mill has limits for zinc and copper and is therefore a
logical source. What, if any, action is necessary to be taken to
ensure that Glendale is removing enough of the zinc and copper
from its wastewater?
I would like to report back our position on this at the next
steering committee meeting on February 1. Please call if you
have any questions. Mike Scoville was present at this past
steering committee meeting when this issue was discussed.

DIVISION OF ENVIRONMENTAL MANAGEMENT
November 17, 1989
MEMORANDUM
TO: Don Safrit
FROM: CMike_$covilk-e—
THRU: Ruth Swanekk�o
Tom Stockton45
Trevor Clements�
SUBJECT: Proposed Expansion of the Siler City WWTP (NPDES No. NC0026441,
Chatham County)
Siler City has requested an expansion of their WWTP from 1.8 MGD to 4.0
MGD and is currently preparing an environmental impact statement (EIS) in
accordance with Division requirements for expansions using public funds.
Also as part of the expansion process, the facility performed a special
instream monitoring program in August, 1989, upon DEM's request. This moni-
toring was in addition to their normal instream monitoring and included five
sites on Loves Creek and the Rocky River. Technical Support has reviewed
the instream data, the past wasteload allocations, and the available biolog-
ical data, and offer the following comments and recommendations regarding
the issuance of an NPDES permit for the proposed expansion.
The current wasteload allocations for the Siler City WWTP, at 1.8 MGD
and 4.0 MGD, are inappropriate. Substandard dissolved oxygen (DO) concen-
trations have been observed upstream and downstream of the discharge even
when the facility was discharging within its permit requirements. It is
expected that frequent unobserved instream violations occur in the Rocky
River below its confluence with Loves Creek. Also, instream data indicate
that under current conditions the DO in the Rocky River sags 1 to 1.5 mg/l
as a direct result of the Siler City discharge. Given 1) the impact of the
effluent on the sensitive Rocky River system, 2) the increasing emphasis
placed on ammonia toxicity, 3) the federally protected habitat of the endan-
gered Cape Fear Shiner downstream in the Rocky River, and 4) the low flow
nature of Loves Creek (DA=7.9 sq. mi., QA=8.7 cfs, 7Q10=0.25 cfs, and
30Q2=0.95 cfs), Technical Support recommends that upon expansion of the
Siler City WWTP the NPDES permit limits be changed to the following:

Sumner Winer
BODS (mg/1)
5
10
NH3 (mg/1)
1
2
DO (mg/1)
6
6
TSS (mg/1)
30
30
Fecal Coliform (#/100 ml)
200
200
pH (SU)
6-9
6-9
Oil 5 Grease (mg/1)
30
30
MBAS (mg/1)
0.5
0.5
Chromium (ug/1)
52
52
Cyanide (ug/1)
5.2
5.2
Mercury (ug/1)
0.012
0.012
Copper (ug/1)
Monitor
Nickel (ug/1)
Monitor
Zinc (ug/1)
Monitor
Silver (ug/1)
Monitor
(Daily Max.)
(Daily Max.)
(Daily Max.)
These limits represent a 26% reduction of BODS loading and a 55.5%
reduction of NH3-N loading from the previous permit and are expected to
significantly reduce the instream impact of the discharge. Technical Sup-
port does not have, at this time, an appropriate model of Loves Creek and
the Rocky River. Therefore, if these limits should be unacceptable to the
City, more instream water quality studies will be required to determine the
appropriate limits, which may or may not be less stringent. The instream
and effluent monitoring requirements should not be changed.
Chlorine may also need to be limited in the permit. Chlorine has been
identified as a constituent in Siler City's wastewater that is contributing
to whole -effluent toxicity. An expansion of the facility from 1.8 MGD to 4.0
MGD represents an increase of the instream waste concentration from 91.8% to
96.1%; any toxic effects of the effluent need to be addressed prior to per-
mitting the expansion. Technical Support recommends that Siler City be
required by the permit to 1) switch to another method of wastewater disin-
fection, 2) dechlorinate their effluent, or 3) meet an effluent chlorine
limitation based on the North Carolina stream standard. The chlorine limit
required would be 17 ug/l.
A priority pollutant analysis was performed on the effluent on October
24, 1989. When the results of this analysis are received, it may be neces-
sary to limit other parameters in the upcoming permit as well. Each of
these issues should be addressed in drafting the 4.0 MGD permit for Siler
City, and it is expected that knowledge of the above recommendations will be
helpful in the EIS planning process for the City.
Please feel free to contact me if you have any questions or comments
regarding this matter.
cc: Arthur Mouberry
Alan Clark
Central Files

0
State of North Carolina
Department of Natural Resources and Community Development
Division of Environmental Management
512 North Salisbury Street • Raleigh, North Carolina 27611
James G. Martin, Governor July 11, 1989 R. Paul Wilms
William W. Cobey, Jr., Secretary Director
r
J �
Mr. Ben Shivar, , Town Manager ; Ali JUL 20 19M9
Town of Siler City
P.G. Box 769
Siler City, N.C. 27344
Dear Mr. Shivar:
Because of public concern over the potential .impact of the
Town's proposed wastewater treatment plant expansion, I have
decided to require that an environmental document be prepared
before a final decision is made on the issuance of the NPDES
permit for the expansion of the facility. This position is
consistent with recently adopted Departmental rules that require
preparation of either an environmental assessment (EA) or an
environmental impact statement (EIS) pursuant to the State
Environmental Policy Act for new wastewater treatment plants or
plant expansions exceeding one MGD (see attachment). I regret
that the issue has arisen at this stage in your permit
preparation but my staff will work with you to minimize the time
required to prepare and consider this documentation. We will
hold your permit application and will delay the public hearing
until after we have had a chance to;review the completed EA or
EIS.
The Division only requires that an environmental assessment
be prepared. If the action to be taken is considered
straightforward, its impacts easily assessed, and possibilities
for public concern minimal, we have seen that in most cases an EA
is adequate. on the other hand, if there are unusual or unique
P.O. Box 27687, Raleigh, North Carolina 27611-7687 Telephone [phone]
An Equal Opportunity .Affirmative Amon Employer

Mr. Ben Shivar, Town Manager
July 11, 1989
Page Two
aspects of the project, potential significant impacts to the
environment or increased public concern, we will recommend that
an EIS be prepared. When there is a question over which is.
appropriate, going ahead with the EIS is often better than
preparing an EA and encountering opposition and possible delays
because of questions involving its adequacy.
In order to help you determine which type of document
should be prepared and what should be included in the document,
we strongly recommend that a scoping meeting be held. The meeting
need not be formal and it could take the form of several small
meetings with individuals who have an interest in the project.
The purpose is to find out what the real concerns are so they can
be addressed in the document. There are a few minimum
requirements provided in the rules implementing the Environmental
Policy Act (copies attached). These should each be addressed
along with other issues found to be significant from the scoping
process. Since the environmental document will be given thorough
State agency and public review, it is better to address the major
concerns in the original work.
I recommend that you or your consultant contact Mr. Boyd
DeVane of our Planning Branch to discuss this process and help
you make decisions on the document's preparation. He can be
reached at 919-733-5083 in Raleigh and will be looking forward to
hearing from you.
/Sincer ly, 71j
R. Paul Wilms
cc: Mr. John Runkle
Rep. Joe Hackney
Mr. Steve Tedder
Mr. Bill Flournoy
Mr. Dennis Ramsey
Mr-. Trevor Clements'
Mr. Tim Donnelley
Shivar.ltr