NCS000245_Raleigh WQ Assessment & Monitoring Plan_20201102

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Water Quality Assessment and Monitoring Plan
January 2010
PERMIT NO. NCS000245
TO DISCHARGE STORMWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
1.0
Purpose................................................................................................................................2
2.0
Water Quality Monitoring Program.................................................................................... 2
2.1 Monitoring Methods............................................................................................... 2
2.2 Sample Types and Frequency................................................................................. 2
2.3 Monitoring Parameters............................................................................................ 2
3.0
Monitoring Sites.................................................................................................................. 3
3.1 Basis for Locating Monitoring Sites....................................................................... 3
3.2 Site Locations/Description...................................................................................... 3
3.3 Site Map.................................................................................................................. 4
4.0
Sample and Data Analysis.................................................................................................. 4
4.1 Sample Analytical Methods.................................................................................... 4
4.2 Quality Assurance................................................................................................... 5
4.3 Record Keeping...................................................................................................... 5
5.0
Data Evaluation and Assessment........................................................................................ 5
5.1 Methods for Evaluating and Assessing Data.......................................................... 5
5.2 Reporting.................................................................................................................6
5.3 Monitoring Plan Revisions..................................................................................... 6

City of Raleigh Water Quality Assessment and Monitoring Plan
January 2010
1.0 Purpose
The purpose of the Water Quality Assessment and Monitoring Program is to monitor and assess
the quality of streams within the City of Raleigh. Information gained from this program may
be used to help identify and eliminate sources of pollution, track short-term and long-term trends,
and, where possible, gauge the effectiveness of stormwater management efforts and programs
conducted by the City.
2.0 Water Quality Monitoring Program
2.1 Monitoring Methods
Monitoring methods utilized in this plan consist of directly accessing the stream to conduct
specified monitoring within the stream channel at a point representative of the overall stream
flow at the time of monitoring. In most cases, this is center channel of the stream. When
possible, staff enter the stream and directly fill sample bottles from the stream flow.
2.2 Sample Types and Frequency
Samples collected under this plan are fixed interval grab samples taken on a quarterly basis at
each monitoring location. A specific day of each calendar quarter (for example - the 3rd Tuesday
of each quarter) is assigned for monitoring to allow for sampling over a range of flows in the
long-term at each monitoring location.
2.3 Monitoring Parameters
Water quality samples collected from each monitoring location are analyzed for a variety of
water quality parameters in a certified laboratory, as detailed in Table 2-1.
Table 2-1. Laboratory Analyzed Water Quality Samples
Parameter
Sample Type
Frequency
E. Coli
Grab
Quarterly
Total Phosphorus
Grab
Quarterly
Turbidity
Grab
Quarterly
Total Suspended Solids
Grab
Quarterly
Total K'eldahl Nitrogen
Grab
Quarterly
Nitrate + Nitrite
Grab
Quarterly
Ammonia Nitrogen
Grab
Quarterly
Copper
Grab
Quarterly
Zinc
Grab
Quarterly
Calcium
Grab
Quarterly
Magnesium
Grab
Quarterly
Total Hardness
Grab
Quarterly
Water quality samples collected from each monitoring location will be field analyzed for the
parameters as detailed in Table 2-2.
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City of Raleigh Water Quality Assessment and Monitoring Plan
January 2010
Table 2-2. Field Analyzed Water Quality Samples
Parameter
Sample Type
Frequency
Dissolved Oxygen
Grab
Quarterly
Conductivity
Grab
Quarterly
H
Grab
Quarterly
Temperature
Grab
Quarterly
3.0 Monitoring Sites
3.1 Basis for Locating Monitoring Sites
One monitoring site is located within each major watershed in the City of Raleigh to characterize
water quality conditions within the assigned watershed. Monitoring sites are typically located at
the downstream most accessible point within the watershed that most accurately characterizes the
water quality within that watershed. Eighteen (18) monitoring locations are utilized within this
Water Quality Monitoring Program to monitor and assess water quality conditions in Raleigh.
3.2 Site Locations/Description
The eighteen (18) monitoring locations have been assigned a Site ID and a description of each
location is provided in Table 3-1.
Table 3-1. Descriptions of Monitoring Locations
Site ID
Watershed
Monitoring Location
BDB 1
Beaverdam Branch
Stream Crossing at Lassister Mill Road
13132
Big Branch
Stream Crossing at Six Forks Road
BBS3
Big Branch South
Stream Crossing at Rock Quarry Road
CC4
Crabtree Creek
Stream Crossing in Umstead Park (0.25 mile west of
Ebenezer Church Road)
CC5
Crabtree Creek
Stream Crossing at New Bern Avenue
HSC6
Hare Snipe Creek
Stream Crossing at Hare Snipe Creek
HC7
House Creek
Stream Crossing at Crabtree Valley Avenue
LBC8
Little Brier Creek
Stream Crossing at I-540
MC9
Marsh Creek
Stream Crossing at Yonkers Road
MC 10
Mine Creek
Stream Crossing at North Hills Drive
PC 11
Perry Creek
Stream Crossing at Perry Creek Road
PHB 12
Pigeon House Branch
Stream Crossing at Crabtree Boulevard
RC 13
Richland Creek
Stream Crossing 1000 feet east of Ebenezer Church Road
RC 14
Richland Creek WF
Stream Crossing at New Falls of Neuse Road
RB 15
Rocky Branch
Stream Crossing at Keeter Center Drive
SC16
Sycamore Creek
Stream Crossing at Umstead Park (0.2 miles west of
Ebenezer Church Road
TC 17
Turkey Creek
Stream Crossing at Ebenezer Church Road
WC18
Walnut Creek
Stream Crossing at Barwell Road
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City of Raleigh Water Quality Assessment and Monitoring Plan January 2010
3.3 Site Map
Monitoring locations have been selected at representative locations in the major watersheds
within the City of Raleigh. Figure 3-1 is a site map of the eighteen (18) monitoring locations.
Figure 3-1. Monitoring Locations
4.0 Sample and Data Analysis
4.1 Sample Analytical Methods
Water quality samples are analyzed at a certified laboratory for several parameters. Table 4-1
provides information on the reporting limits (RL) and analytical methods used to analyze water
quality samples collected as part of the Water Quality Assessment and Monitoring Program.
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City of Raleigh Water Quality Assessment and Monitoring Plan
January 2010
Table 4-1. Laboratory Analytical Methods and Reporting Limits (RL)
Parameter
RL
Units
Method
Sample
Volume
Holding
Time
Bottle
Preservative
Total Phosphorus
0.05
mg/L
EPA 365.4
250 mL
28 Days
H2SO4
Turbidity
1.0
NTU
EPA 180.1
16 oz.
48 Hrs.
None
Total Suspended Solids
1.0
mg/L
EPA 2540D
1 L
7 Days
None
Total Kjeldahl Nitrogen
0.25
mg/L
EPA 351.2
250 mL
28 Days
H2SO4
Nitrate + Nitrite
0.02
mg/L
EPA 353.2
8 oz.
28 Days
H2SO4
Ammonia Nitrogen
0.02
mg/L
EPA 350.1
250 mL
28 Days
H2SO4
Copper
0.5
mg/L
EPA 200.8
1 L
6 Months
NH03
Zinc
0.5
mg/L
EPA 200.8
1 L
6 Months
NH03
E. Coli
1.0
MPU/
100 mL
Idexx Quantitray
Colilert E.Coli
250 mL
30 Hrs.
Sodium
Thiosulfate
Calcium
0.1
mg/L
EPA 200.8
500 mL
6 Months
N1103
Magnesium
0.1
mg/L
EPA 200.8
500 mL
6 Months
N1103
Total Hardness
0.662
mg/L
Calculation
500 mL
6 Months
N1103
4.2 Quality Assurance
Water quality samples are collected by City of Raleigh Stormwater Utility Division staff with
procedures and protocols for sample collection and sample handling as outlined in the most
recent version of Standard Procedure SW-201 Stream Sampling of Conventional Parameters.
All laboratory analyzed water quality samples are delivered to a certified laboratory which
follows strict protocols for preservation, equipment calibration and maintenance, analysis
protocols, quality assurance/quality control.
4.3 Record Keeping
All records and data generated under the Water Quality Assessment and Monitoring Program
will be maintained for a minimum period of five years. In most case, field data and laboratory
are stored in electronic format. All laboratory information, such as maintenance and calibration
records will be kept on file at the certified laboratory.
5.0 Data Evaluation and Assessment
5.1 Methods for Evaluating and Assessing Data
As data is collected, the City analyzes the various pollutant parameters in the program and
conducts analysis on the data to determine trends, where possible. It should be noted that in the
earlier years of monitoring program, only a limited number of data points will be generated due
to the frequency of monitoring. This will make proper statistical analysis difficult during the
first permit cycle, however, as more data is generated over several years, statistical analysis to
determine trends will become more useful. At a minimum, data will be graphically represented
to visualize trends.
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City of Raleigh Water Quality Assessment and Monitoring Plan
January 2010
5.2 Reporting
Data results are reported in Raleigh's NPDES Annual Report. Report discussions will include
the number of samples collected, the number and types of parameters analyzed, and data analysis
activities to determine trends.
5.3 Monitoring Plan Revisions
The City of Raleigh will review the monitoring plan annually as part of the data analysis and
annual report process to determine if any revisions to the plan are necessary based on the
previous year's assessment and monitoring activities. If revisions are necessary, the City will
revise the plan and submit the revisions to the North Carolina Department of Environment and
Natural Resources Division of Water Quality for review and approval.
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