HomeMy WebLinkAboutNC0087670_Draft Permit_20171004Water Resources
ENVIRONMENTAL QUALITY
October 4, 2017
Benjamin Carawan, Utilities Superintendent
Currituck County
734 Ocean Trail
Corolla, North Carolina 27927
Dear Mr. Carawan:
ROY COOPER
Govei not
MICHAEL S. RAGAN
Secy etag
S JAY ZIMMERMAN
Director
Subject: Review of NPDES Permit DRAFT NCO087670
Southern Outer Banks Water System, Class PC -II
734 Ocean Trail, Corolla
Currituck County
In response to your request to renew the subject NPDES permit (received March 21, 2017), the
Division of Water Resources (DWR or the Division) hereby transmits this draft for your review
and comment. Please review this document carefully to assure your understanding of the permit
limits and monitoring conditions, and to correct errors, if any.
Concurrent with this notification, the Division will solicit public comment on this draft by
publishing a notice in newspapers having circulation in the general Currituck County area, as
required by the NPDES Program. Please provide your written comments, if any, to me via email
[joe.corporon@ncdenr.gov], or write to my attention care of NCDEQ / DWR / NPDES Program
no later than November 10, 2017, approximately 30 days after receiving this letter. Your written
comments are welcome, but are not mandatory.
Renewal Summary — We note that Currituck County has made no significant changes in its
treatment systems processes since last renewal. We have therefore only updated your facility
description and site map; updated table and footnotes in section A. (1.), and updated text for
Discharge Monitoring Electronic Reporting. However, we have made significant changes to
your instream sampling requirements.
Changes to the Previous Permit:
1. DWR updated the facility description and compliance requirement (see Supplement
to Permit Cover Sheet).
2. Considering that this facility discharges at a notably low instream waste
concentration [IWC = 0.67%] compared to the receiving waterbody (Atlantic
Ocean), and because instream monitoring data analyses suggest no discernable
impact either "upstream or downstream" of the outfall (see Fact Sheet attachments),
the Division hereby discontinues as redundant all instream monitoring (Upstream
and Downstream); these are deleted from the permit.
3. Based on current WTP permitting guidance, the Division no longer requires
monitoring of effluent parameters Dissolved Oxygen and Temperature; these are
deleted from the permit.
Benjamin Carawan, Utilities Superintendent
Currituck County
October 4, 2017
Page 2
Division records show that you have successfully registered with the eDMR Program. Please be
reminded that until the state's eDMR application is approved compliant with EPA's Cross -
Media Electronic Reporting Regulation (CROMERR), all permittees must continue to submit
hardcopy of DMRs as backup to eDMR reporting [see permit section A. (3.)].
Following the mandatory 30 -day public comment period, the Division will review all pertinent
comments and take appropriate action prior to issuing your NPDES permit final. If you have
questions concerning this draft, please e-mail me oS-c4ll my direct line (919) 807-6394.
Xe R. Corporo , L.G.
WR/ NPDEA Permitting
Enclosure: NPDES Permit NCO087670
hc• NPDES Program Files
ec WaRO / SWPS, David May, Robert Tankard, Will Hart, (Draft and Fact Sheet)
OCU; Maureen Kinney (Draft and Fact Sheet)
ATB; Susan Meadows, Cindy Moore (Draft and Fact Sheet)
Permit NCO087670
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
(NPDES)
h the provisions of North Carolina General' ta` tute`l 3-215.1 other lawful standards
In compliance with p
and regulations promulgated and adopted by the �T4orth Carolina Environmental Management
Commission, and the Federal Water Pollu ion Control Act, a�samended,
Curr1
is hereby authorized
a facility located at the
Currituc cCounty,0uter Banks Water System
�'73f4 Ocean Trai41-(Rote� 2), Corolla
&yKi�ck;/-6ounty
to receiving waters designated as the Atlai
accordance with effluent limitations, mora
III, and IV hereof.
The permit shall become effective
ean (downstream of the Pasquotank River Basin) in
requirements, and other conditions set forth in Parts I, II,
, 2017.
This permit and the authorization to discharge shall expire at midnight on December 31, 2022.
Signed this day , 2017.
S. Jay Zimmerman, P.G., Director
Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 7
Permit NCO087670
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby
revoked. As of this permit issuance, any previously issued permit bearing this number is no longer
effective. Therefore, the exclusive authority to operate and discharge from this facility arises under the
permit conditions, requirements, terms, and provisions included herein.
Currituck County
is hereby authorized to:
1. continue to operate a wastewater treatment and dispos
production [design flow to 3.09 MGD], discharging,4
filter backwash, and ion -exchange backwash/regenera
• two (2) each influent settling /
different sources
• dual (2) treatment trains
o reverse osmosis
o greensand / ion,
• wastewater
• disinfection
• final effluent sampling 'ofl
• appurtenant piping to outfa
• dual (2) effluent diffusers (
in`sup ort of potable -water
iosis re'ectt water, greensand
,water to\jL00 MGD utilizing;
(1E basins \fo\rraaw` water
1 source, water
;hallow -well source water
t from`oth\ trains]
hl rino ati6n)
these facilities located at the Currituck County Outer Banks Water System south of Corolla, 734 Ocean
Trail (Route 12), then
2. discharge from said treatment works via Outfall 001, at a location specified on the attached map,
into the Atlantic Ocean [stream index 99-(7)], a waterbody currently classified SB, located
downstream of the Pasquotank River Basin (subbasin 03-01-54).
Page 2 of 7
Permit NCO087670
PART I
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[ NCAC 02B 0400 et seq. and 0213.0500 et seq.]
Beginning on the effective date of this permit and lasting until expiration, the permittee is authorized to
discharge from Outfall 001. Such discharges shall be limited, monitored and reported 1 by the permittee
as specified below:
EFFLUENT
CHARACTERISTICS
(PARAMETER CODES)
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
Location
Flow
50050
/e/oitir>uuous
Recording
Effluent
Total Suspended Solids
C0530
30.0 mg/L
45.0 mg/L/
\\�Weel�y\
Composite
Effluent
Total Residual Chlorine 2
50060
13 ggoZ/2
Weekl�\\
Grab
Effluent
pH
00400
Not < 6.8 or > 8.5 s u,\
`Weekly
\ Grab
Effluent
Turbidity
00070
�\2/ !Rnth
\`Grab
Effluent
Conductivity
00094
,\
\2/,Month
Q,omposite
Effluent
Salinity
00480
\\
2/ Ionth
Composite
Effluent
Total Dissolved Solids
70295
�� �� \
\ 2/Mbnth-�>
Composite
Effluent
Dissolved Oxygen
00300
% �� ��/j
\284tli
Grab
Effluent
Ammonia (NH3_N)
00610
'\\` \
Monthly
Composite
Effluent
WET -testing Chronic 3
TG3 E
Monitodand Report
Quarterly
Composite
Effluent
Total Nitrogen (TN) 1160610
�\\ \\�`\��J'�
Quarterly
Composite
Effluent
Total Phosphorus (TP)
C0\600�
\\
Quarterly
Composite
Effluent
Footnotes:
1 The Permittee shall submit monthly Discharge Monitoring Reports (DMRs) electronically using DWR's
Electronic Discharge Monitoring Report [eDMR] Program, as detailed herein [see Section A. (3)].
2. The permittee shall comply with TRC limit and monitor only if chlorine (or a derivative) is used to
disinfect. The Division shall consider compliant all effluent TRC values reported below 50 gg/L.
However, the Permittee shall continue to record and submit all values reported by North Carolina -
certified test methods (including field certified), even if these values fall below 50 gg/L.
3. Whole Effluent Toxicity (WET) testing, Chronic [TGP3E] using Mysidopsis Bahia @ 0.67% effluent
concentration [established by diffuser modeling]; Quarterly samples to be collected during January,
April, July, and October [see A. (2.)].
Condition: The Permittee shall discharge no floating solids or foam visible in other than trace amounts.
Page 3 of 7
Permit NCO087670
A. (2.) CHRONIC TOXICITY - MONITORING ONLY (QUARTERLY)
[NCAC 0213 .0500 et seq.]
The permittee shall perform quarterly chronic toxicity tests using procedures described below to establish
compliance with the permit condition. Sampling and analyses will be performed during the months of January,
April, July, and October at an effluent concentration of 0.67 % [established by diffuser modeling]. Effluent
sampling shall be performed at the NPDES permitted final discharge outfall below all treatment processes.
All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge
Monitoring Form (MR -1) for the months in which tests were performed, using the parameter code TGP3E for the
pass/fail results and THP3E for the Chronic Value. Additionally, DWQ $orm AT -4 (original) is to be sent to the
following address: ��—�
Attention: North Carolina Division of Water
Water Sciences Section
1621 Mail Service Center
Raleigh, N.C. 27699-1621
Completed aquatic toxicity test forms shall be filed
after the end of the reporting period for which the ri
Test data shall be complete and accurate and-mclude all
association with the toxicity tests, as well as all dos /,re:
sample must be measured and reported if chlorine is em
Sciences Seetion no later than 30 days
iysical measurements performed in
ual chlorine of the effluent toxicity
of the waste stream.
Should there be no discharge/ofiflow from the facility during a month in which toxicity monitoring is required, the
permittee will complete theinformation located.at the top of-the4quatic toxicity (AT) test form indicating the
facility name, permit number, pipe number, county, and themonth/year of the report with the notation of "No
Flow" in the comment area of the form\, The report shall be/submitted to the Environmental Sciences Section at the
address cited above.
Should the permittee fail to momtor during a month in which toxicity monitoring is required, then monthly
monitoring will begin immediately. Upon submission of a valid test, this monthly test requirement will revert to
quarterly in the months specified above. Should any test data from this monitoring requirement or tests performed
by the North Carolina Division of Water Quality indicate potential impacts to the receiving stream, this permit may
be re -opened and modified to include alternate monitoring requirements or limits.
If the pernuttee monitors any pollutant xr-ore frequently than required by this permit, the results of such monitoring
shall be included in the calculation & reporting of the data submitted on the DMR and all AT form submitted.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum control organism
survival, minimum control organism reproduction, and appropriate environmental controls, shall constitute an
invalid test and will require immediate follow-up testing to be completed no later than the last day of the month
following the month of the initial monitoring.
USE OF A DIFFERENT TEST ORGANISM
The permittee may request the use of a different test organism upon documentation that the alternate test organism
would provide an equal or greater level of protection and is appropriate based on the characteristics of the discharge
and receiving stream. Such documentation would consist of one of the following:
1. For saltwater classified streams, a fathead minnow may be assigned as the acute testing species if the
salinity of the receiving stream at the point of discharge is <5 ppt throughout the tidally influenced
Page 4 of 7
Permit NCO087670
cycle. This determination may be based on the best professional judgment of DWR staff or data
collection provided by the permittee and approved by DWR staff. This evaluation should include
vertical profiles of salinity/conductivity measurements at both high tide and low tide over several 24 -
hr cycles.
2. Three consecutive "side-by-side" tests with results indicating that the alternate test organism is as
or more sensitive to the facility's effluent. Each test series would consist of two separate toxicity
tests conducted on the same sample of effluent with the length of exposure specified by the permit,
the only difference between the tests being the organism used.
3. An alternate plan developed by the permittee and approved by the Aquatic Toxicology Unit that
demonstrates an equal level of protection is offered by the test organism.
For items 2 and 3, it must also be demonstrated that viable and standardized culture techniques are available for that
organism and standardized testing methodologies have been developed and allidated. This demonstration should
meet guidance provided by EPA in Section 6 of EPA -821-R-02-012 "Short Term Methods for Estimating the Acute
Toxicity of Effluents and Receiving Waters to Freshwater Organisms{ Fifth\Edition 2002."
Requests to use a different test organism and supporting
of Water Resources, Water Sciences Section (at the addb
A. (3.) ELECTRONIC REPOR°TINQOF DIS(
[G.S. 143-215.1(b)]
Federal regulations require electronic submittal ofall di
reports. The final NPDES Electromc-Reporting,Rule w�
2015.
to North Carolina Division
RING REPORTS
monitoring reports (DMRs) and program
-d and became effective on December 21,
NOTE: This special condition supplements br'supersedes the following sections within Part II of this
permit (Standard Conditions for NPDES Permi`ts):
• Section B. (11.) Signatory Requirements
• Section D. (2.) Reporting
• Section D. (6.) Records Retention
• Section E. (5.) Monitoring Reports
1. Reporting Requirements [Supersedes Section D. (2.) and Section E. (5.) (a)1
The permittee shall report discharge monitoring data electronically using the NC DWR's Electronic
Discharge Monitoring Report (eDMR) internet application.
Monitoring results obtained during the previous month(s) shall be summarized for each month and
submitted electronically using eDMR. The eDMR system allows permitted facilities to enter
monitoring data and submit DMRs electronically using the internet. Until such time that the state's
eDMR application is compliant with EPA's Cross -Media Electronic Reporting Regulation
(CROMERR), permittees will be required to submit all discharge monitoring data to the state
electronically using eDMR and will be required to complete the eDMR submission by printing,
signing, and submitting one signed original and a copy of the computer printed eDMR to the
following address:
Page 5 of 7
Permit NC0087670
NC DEQ / Division of Water Resources / Water Quality Permitting Section
ATTENTION: Central Files
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the facility
being physically located in an area where less than 10 percent of the households have broadband
access, then a temporary waiver from the NPDES electronic reporting requirements may be granted
and discharge monitoring data may be submitted on paper DMR forms (MR 1, 1. 1, 2, 3) or alternative
forms approved by the Director. Duplicate signed copies shall be submitted to the mailing address
above. See "How to Request a Waiver from Electronic Reporting" section below.
Regardless of the submission method, the first DMR is due
issuance of the permit or in the case of a new facility, on th
commencement of discharge.
Starting on December 21, 2020, the permittee
monitoring data and reports, when applicable:
Sewer Overflow/Bypass Event Reports;
Pretreatment Program Annual Reports;
Clean Water Act (CWA) S,ection,316(b;
The permittee may seek an
Waiver from Electronic Re
2. Electronic Submissions
In accordance with 40 CFR 122:41(1)(9);
each electronic submission. The prnitti
initial recipient for the electronic submis
wai
t day of the month following the
of the month following the
y report\the following compliance
ivision (see "How to Request a
ittee must identify the initial recipient at the time of
use the EPA's website resources to identify the
Initial recipient of electronic NPDES information from NPDES-regulated facilities means the entity
(EPA or the state authorized by EPA to implement the NPDES program) that is the designated entity
for receiving electronic NPDES data [see 40 CFR 127.2(b)].
EPA plans to establish a website that will also link to the appropriate electronic reporting tool for each
type of electronic submission and for each state. Instructions on how to access and use the appropriate
electronic reporting tool will be available as well. Information on EPA's NPDES Electronic
Reporting Rule is found at: http://www2.epa. ov�pliance/final-national-pollutant-discharge-
elimination-s st�pdes-electronic-reporting-rule.
Electronic submissions must start by the dates listed in the "Reporting Requirements" section above.
Page 6 of 7
Permit NC0087670
How to Request a Waiver from Electronic Reporting
The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an
electronic reporting waiver, a permittee must first submit an electronic reporting waiver request to the
Division. Requests for temporary electronic reporting waivers must be submitted in writing to the
Division for written approval at least sixty (60) days prior to the date the facility would be required
under this permit to begin submitting monitoring data and reports. The duration of a temporary
waiver shall not exceed 5 years and shall thereupon expire. At such time, monitoring data and reports
shall be submitted electronically to the Division unless the permittee re -applies for and is granted a
new temporary electronic reporting waiver by the Division. Approved electronic reporting waivers
are not transferrable. Only permittees with an approved reporting waiver request may submit
monitoring data and reports on paper to the Division for the penodAhat the approved reporting waiver
request is effective.
Information on eDMR and the application for a tem
the following web page: http://deq.nc.gov/about/di`
3. Signatory Requirements
All eDMRs submitted to the permit issuing auth
Section B. (11.)(a) or by a duly authorized represe
B. (I 1.)(b). A person, and not a postiori must be
purposes.
For eDMR submissions; the per-son,si
account and login credentials toca cel
eDMR system, registering.for eDMR
web page:
waiver are found on
be'signed by a person described in Part II,
of that\person as described in Part II, Section
d signatory authority for eDMR reporting
i
%the DMR must obtain an eDMR user
For more information on North Carolina's
ing an- eDMR user account, please visit the following
Certification. Any person submitting<'an electronic DMR using the state's eDMR system shall make
the following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF CERTIFICATION
WILL BE ACCEPTED:
"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. "
4. Records Retention [Supplements Section D. (6.)1
The permittee shall retain records of all Discharge Monitoring Reports, including eDMR submissions.
These records or copies shall be maintained for a period of at least 3 years from the date of the report.
This period may be extended by request of the Director at any time [40 CFR 122.41].
Page 7of7
Currituck County
Southern Outer Banks Water System
Receiving Stream: Atlantic Ocean [99-(7)] Stream Class: SB
Drainage Basin: Pasquotank (downstream) Sub -Basin: 03-01-54
Latitude: 360 18' 55" N Long: 75° 48' 15" W
State Grid/Quad: B35SE / Mosey Islands, NC
Facility
Location Am"
not to scale
NPDES Permit NC087670
North
Currituck County
DEQ/DWWNPDES
FACT SHEET FOR RENEWAL
NPDES Permit NCO087670
Reviewer: Joe R. Corporon, L.G.
Facility Information
Applicant/
Facility Name:
Currituck County — Southern Outer Banks Water System
Applicant Address:
P.O. Box 39; Currituck, North Carolina 27929
Facility Address:
734 Ocean Trail Route 12), south of Corolla, NC 27927
Permitted Flow
1.0 MGD (proposed)
Type of Wastes:
Reverse osmosis reject wastewater, greensand filter backwash and
ion -exchange wastewater
Facility/Permit Status:
Class PC -II / Renewal
County:
I Currituck County
Miscellaneous
Receiving Stream:
Atlantic Ocean
Regional Office:
Washington
Stream Classification:
SB
State Grid /
USGSQuad:
B35SE /Mossey Island,
NC
IWC %
0.67%
8 -Digit HUC:
03010205
Subbasin:
03-01-54
Review Date:
21Sep2017
Drainage Area (mit :
NA
Facility Location
AANV
Lat. 36° 18' 55" N Long. 75° 48' 15" W
Summer 7Q 10 (cfs)
230 from model)
Winter 7Q 10 cfs :
NA
Average Flow cfs :
NA
303(d) Listed?
Yes
(Fish for mercury)
Facility History: Currituck County - Southern Outer Banks Water System (County WTP) treats
filter backwash wastewater at flows ranging from 0.600 MGD to 1.0 MGD depending on
potable -water demand. Prior to last renewal, they acquired several private water systems
triggering an expansion of treatment facilities. Additional water sources included Monterey
Shores (216,000 GPD), Pine Island (306,000 GPD), and the Currituck Club (432,000 GPD).
These previous WTPs abandoned their treatment systems (taken off line), but existing supply
wells remain in service. Total influent treatment design therefore approaches 3.09 MGD, per the
application received 21 Mar2017.
Treatment System Summary: County WTP utilizes two (2) separate treatment trains to
produce potable water. One train applies reverse osmosis (RO) to treat deep -well water (yield to
1.756 MGD); the second train combines greensand and ion -exchange (IO) technology to treat
raw water from shallow wells (yield to 1.334 MGD). The Permittee's flow diagram, estimates
RO reject at 70% of discharge. Actual average Jan2013-Aug2017 = 0.502 MGD [max 1.15; min
0.115 MGD].
The Permittee treats wastewaters using duel trains, blends them together, samples the final
effluent for compliance, then discharges to the Atlantic Ocean via Outfall 001 located
approximately 250 feet offshore at Corolla Beach. Discharge terminates at an effluent diffuser
consisting of dual 200 -foot long, 20 -slot wellscreens, each buried approximately 15 feet below
Fact Sheet for Permit Renewal - Sep2017
NPDES NCO087670
Page 1
the bottom of the ocean floor; modeled by CORMIX to establish IWC. Approximate annually,
RO filter sludge is transported across the street to the local WWTP for treatment.
Compliance Review: This facility's compliance record is excellent with no permit limit or
monitoring violations during the past permit cycle.
Toxicity Testing: Since January 2013, the recent WET -test record indicates 14 consecutive
passes. Quarterly Chronic WET testing [TGP3E] reports "Pass" for 15 of 16 quarters — only one
failure sampled 22Jan2015. In keeping with Division WTP Guidance for facilities with an
instream waste concentration (IWC) of < 0.25% [IWC = 0.67%], Chronic WET -testing will
continue — [TGP3E] monitoring only. No other changes recommended.
Instream Sampling Data -- The present permit requires monthly upstream and downstream
monitoring for dissolved oxygen, temperature, conductivity, salinity, and pH. Generally,
sampling results data suggest no significant differences between upstream and downstream
(Jan2013-Aug2017), but rather natural changes annually in response to weather and temperature
(see XL comparison Upstream vs. Downstream).
Reasonable Potential Analysis (RPA) -- There are currently no parameters of concern (POCs)
generating data appropriate for RPA.
Summary of Proposed Changes:
1. Updated the facility description and compliance requirement (Supplement to Permit
Cover Sheet)
2. Based on current WTP permitting guidance, the parameters Dissolved Oxygen and
Temperature no longer require monitoring and are deleted from the permit.
3. Considering that this facility discharges at a remarkably low IWC (0.67%) compared to
the Atlantic Ocean, and because instream analyses (Mar2014-Sep2017) suggest no
discernable impact to the receiving waterbody (see attached summaries), the Division
hereby discontinues all Instream Monitoring (upstream and downstream).
Proposed Schedule for Issuance:
Draft Permit to Public Notice:
Permit Scheduled to Issue:
NPDES Contact:
October 4, 2017
November 24, 2017
If you have questions regarding any of the above information or on the attached permit, please
email Joe R. Corporgn; LAG. Uoe.wWoron@ncdenr.gov] or call my direct line (919) 807-6394.
sic
Fact Sheet for Pennit Renewal - Sep2017
NPDES NCO087670
Page 2
NCO087270 CURRITUCK COUNTY WTP - INSTREAM SAMPLING ANALYTICAL RESULTS COMPARED
Upstream Dissolved Oxygen (DO) - (Jan2013 to Aug2017)
12
9.9 9.7
9.4
10 8.4 8.8 8.9 8.9 8.3 V8.49.2 8.5
8 7.5 7.7 7.3 7. 7 8 7.67.9 7.8 8.06
6:2' 'B.q• ..... ... .26:2..fi .G..2 ... .......................... .6;................ 18.3.........
6
5.75.
4
2
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Monthly Sampling
Downstream Dissolved Oxygen (DO) - (Jan2013 to Aug2017)
12
10 9.1 9.4 9 9.2 9.8 9.5
8.8
8.2 7.8 8.4 8.2 .1
8 7 7 7.3 7 7.4 7 6.9 7. 7.4 7.
6 6 6.1 6.2 6.2 5.9 6.1
6 7 5.
E
4
2
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Monthly Sampling
w000
Upstream Conductivity (Jan2013 to Sug2017)
50000
40000
E
0 30000
E
20000
10000
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 3132 33 34 35
Monthly Sampling
Downstream Conductivity (Jan2013 to Aug2017)
60000
50000
40000
E
0 30000
E
0
20000
10000
0
1 2 3 4 5 6 7 8 9 30 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Monthly Sampling