HomeMy WebLinkAboutChapter 8
Chapter 8
Stormwater and Wastewater Programs
8.1 NPDES Wastewater Discharge Permit Summary
Discharges that enter surface waters through a pipe,
ditch or other well-defined point of discharge are
broadly referred to as 'point sources'. Wastewater point
source discharges include municipal (city and county)
and industrial wastewater treatment plants and small
domestic wastewater treatment systems serving schools,
commercial offices, residential subdivisions and
individual homes. Stormwater point source discharges
include stormwater collection systems for
municipalities that serve populations greater than 100,000 and stormwater discharges associated
with certain industrial activities. Point source dischargers in North Carolina must apply for and
obtain a National Pollutant Discharge Elimination System (NPDES) permit. Discharge permits
are issued under the NPDES program, which is delegated to DWQ by the Environmental
Protection Agency.
The primary pollutants associated
with point source discharges are:
* oxygen-consuming wastes,
* nutrients,
* color, and
* toxic substances including chlorine,
ammonia and metals.
Currently, there are 35 permitted
wastewater discharges in the Little
Tennessee River basin. Table 15 provides
summary information (by type and
subbasin) about the discharges. Various
types of dischargers listed in the table are
described in the inset box. Facilities are
mapped in each subbasin chapter. For a
complete listing of permitted facilities in
the basin, refer to Appendix V.
Types of Wastewater Discharges
Major Facilities: Wastewater Treatment Plants with
flows ≥1 MGD (million gallons per day); and some
industrial facilities (depending on flow and potential
impacts to public health and water quality).
Minor Facilities: Facilities not defined as Major.
100% Domestic Waste: Facilities that only treat
domestic-type waste (from toilets, sinks, washers).
Municipal Facilities: Public facilities that serve a
municipality. Can treat waste from homes and
industries.
Nonmunicipal Facilities: Non-public facilities that
provide treatment for domestic, industrial or
commercial wastewater. This category includes
wastewater from industrial processes such as
textiles, mining, seafood processing, glass-making
and power generation, and other facilities such as
schools, subdivisions, nursing homes, groundwater
remediation projects, water treatment plants and
non-process industrial wastewater.
Roughly sixty percent of NPDES
permitted wastewater flow in the Little
Tennessee River basin is from major
municipal wastewater treatment plants
(WWTP). Nonmunicipal discharges also
contribute substantial wastewater flow into
the Little Tennessee River basin.
Facilities, large or small, where recent data
show problems with a discharge are
discussed in each subbasin chapter.
Chapter 8 – Stormwater and Wastewater Programs 121
Table 15 Summary of NPDES Dischargers and Permitted Flows for the Little Tennessee River
Basin
Little Tennessee River Subbasins
Facility Categories 01 02 03 04 Total
Total Facilities 11 20 1 3 35
Total Permitted Flow (MGD)3.39 3.39 0.002 0.64 7.422
Facilities Grouped by Size
Major Discharges 1100 2
Total Permitted Flow (MGD)1.65 1.50 0 0 3.15
Minor Discharges 10 19 1 3 33
Total Permitted Flow (MGD)1.74 1.89 0.002 0.64 4.27
Facilities Grouped by Type
100% Domestic Waste 81310 22
Total Permitted Flow (MGD)0.24 0.048 0.002 0 0.29
Municipal Facilities 3302 8
Total Permitted Flow (MGD)3.15 2.6 0 0.64 6.39
Nonmunicipal Facilities 0401 5
Total Permitted Flow (MGD)0 3.08 0 -- 3.08
8.2 DWQ Stormwater Programs
There are several different stormwater programs administered by DWQ and local jurisdictions.
One or more of these programs affects many communities in the Little Tennessee River basin.
The goal of the DWQ stormwater discharge programs is to prevent pollution from entering the
waters of the state via stormwater runoff. These programs try to accomplish this goal by
controlling the source(s) of pollutants. These programs include NPDES Phase I and II,
HQW/ORW stormwater requirements, and requirements associated with the Water Supply
Watershed Program. Local governments that are or may be affected by these programs are
presented in Table 17.
8.2.1 NPDES Phase I
Phase I of the EPA stormwater program started with Amendments to the Clean Water Act
(CWA) in 1990. Phase I required NPDES permit coverage to address stormwater runoff from
medium and large stormwater sewer systems serving populations of 100,000 or more. There are
no NPDES Phase I stormwater permits issued to communities in the basin.
Phase I also had requirements for eleven categories of industrial sources to be covered under
stormwater permits. Industrial activities which require permitting are defined in ten categories
ranging from sawmills and landfills to manufacturing plants and hazardous waste treatment,
storage or disposal facilities. Construction sites disturbing greater than five acres were also
required to obtain an NPDES stormwater permit under Phase I of the EPA stormwater program.
Excluding construction stormwater general permits, there are 106 general stormwater permits
and 6 individual stormwater permits. Refer to the subbasin chapters for more information on
stormwater programs and permits and a complete listing of individual permits in Appendix V.
122 Chapter 8 – Stormwater and Wastewater Programs
8.2.2 NPDES Phase II
The Phase II stormwater program is an extension of the Phase I program that expands permit
coverage to include smaller municipalities below 100,000 populations. The local governments
permitted under Phase II are required to develop and implement a comprehensive stormwater
management program that includes six minimum measures.
1. Public education and outreach on stormwater impacts;
2. public involvement/participation;
3. illicit discharge detection and elimination;
4. construction site stormwater runoff control;
5. post-construction stormwater management for new development and redevelopment; and
6. pollution prevention/good housekeeping for municipal operations.
Construction sites greater than one acre will also be required to obtain an NPDES stormwater
permit under Phase II of the EPA stormwater program in addition to erosion and sedimentation
control approvals.
Those municipalities and counties required to obtain a NPDES stormwater permit under the
Phase II rules are identified using 1990 US Census Designated Urban Areas and the results of the
2000 US Census. Based on federal census data, EPA identified 123 cities, including, and 33
counties in North Carolina that would be required to obtain permits for stormwater management.
The EPA delegated Phase II implementation to each state and then in 1999 the Division of Water
Quality and the Environmental Management Commission (EMC) initiated a rulemaking process.
Stormwater Management Rule Update:
In 2002, the EMC adopted temporary stormwater rules and by 2003 had adopted permanent rules
that were to become effective August 1, 2004. In early 2004, the Rules Review Commission
(RRC) objected to the rules for failure to comply with the Administrative Procedures Act and
lack of statutory authority. The EMC challenged the decision of the RRC in court (EMC v. RRC
04 CVS 3157). A Wake County Superior Court ruled in the EMC’s favor and the RRC
subsequently approved the EMC’s rules. However, while the case was pending the legislature
enacted a separate set of requirements in 2004 that were designed to replace the EMC rules.
These rules include NPDES stormwater rules covering owners and operators of storm sewer
systems and State stormwater rules covering activities in urbanizing areas. The EMC amended
the rules at their November 10, 2005 meeting to address objections raised by the RRC at their
October 2005 meeting. The inconsistency between the legislative requirements and the EMC
rules necessitated consideration of Senate Bill 1566 in the 2006 short session. The legislature
approved Session Law 2006-246, Senate Bill 1566 in 2006.
Senate bill 1566 provides that development projects in Phase II municipalities and counties that
cumulatively disturb one acre or more of land must comply with the post-construction
stormwater standards set out in the bill. The bill sets out criteria whereby unincorporated areas
of counties will be subject to Phase II requirements. Under these criteria 25 counties are fully
covered, while 8 counties have portions that are subject to the stormwater requirements. The bill
Chapter 8 – Stormwater and Wastewater Programs 123
also provides a designation and petition process by which additional local governments and other
entities may be required to obtain a stormwater management permit.
The bill sets out stormwater controls that are based on a project’s level of density and its
proximity to Shellfish Resource Waters. Shellfish Resource Waters are waters classified by the
EMC as Class SA waters (shellfish growing waters) that contain an average concentration of 500
parts per million of natural chloride ion (saltwater).
The Water Quality Committee (WQC) met in November 2006 and directed DWQ Staff to return
to the January 2007 WQC meeting with proposed amendments to the State Stormwater Rules.
These rules will extend the coastal post-construction stormwater controls in Session Law 2006-
246 to all 20 Coastal Counties (Table 16).
Low Density Projects
Development projects that are located within one-half mile of and draining to Shellfish Resource
Waters are considered low density if they contain no more than 12 percent built-upon area. A
project that is not located within one-half mile of Shellfish Resource Waters is a low density
project if it contains no more than 24 percent built-upon area or no more than two dwelling units
per acre. Low density projects must use vegetated conveyances to the maximum extent
practicable to transport stormwater runoff from the project.
High Density Projects
Projects that are located within one-half mile of and draining to Shellfish Resource Waters are
considered high density if they contain more than 12 percent built-upon area. A project that is
not located within one-half mile of Shellfish Resource Waters is a high density project if it
contains more than 24 percent built-upon area or more than two dwelling units per acre. High
density projects must use structural stormwater management systems that will control and treat
runoff from the first one inch of rain unless the project is in a coastal county, in which case the
project must use structural stormwater management systems that will control and treat runoff
from the first one and one-half inches of rain. In addition, projects that are located within one-
half mile and draining to Shellfish Resource Waters must control and treat the difference in the
stormwater runoff from the pre-development and post-development conditions for the one-year
twenty-four hour storm as well as meet certain design standards.
Implementation
The bill provides an implementation schedule that requires regulated entities to apply for an
NPDES stormwater management permit within 18 months of being notified that it is a regulated
entity subject to the requirements of this act. A regulated entity must implement its post-
construction program no later than 24 months from the date the permit is issued and fully
implement its permitted program within five years of permit issuance. City of Jacksonville and
Onslow County have both submitted applications for Phase II.
The bill authorizes the EMC to adopt Phase II stormwater management rules. If the EMC does
adopt rules, the rules must be substantially identical to the provisions of this act and will be
automatically subject to review by the General Assembly and not subject to review by the RRC.
The bill became effective retroactively to July 1, 2006.
124 Chapter 8 – Stormwater and Wastewater Programs
Table 16 Major Post-Construction Stormwater Controls in SL 2006-246
Shellfish Resource
Waters*
(SA Waters w/ > 500 ppm
chlorides)
SA Designated Waters –
Not Shellfish Resource
Waters*
Coastal County –
Not SA
Designated
Waters
Non – Coastal
County
Low Density
Threshold 12% 24% 24% 24%
Storm Design for
High Density
Difference in pre and post-
development for 1-yr, 24-
hour storm**
Runoff from first 1.5
inches of rain
Runoff from first
1.5 inches of rain
Runoff from first
1 inch of rain
Setback 30 feet 30 feet 30 feet 30 feet
Other Controls
No new points of s/w
discharge
No increase in rate,
volume, or capacity in
existing conveyances
Infiltration up to
1-yr, 24-hr storm
Diffuse flow in excess of
1-yr, 24-hr storm
No new points of s/w
discharge
No increase in rate,
volume, or capacity in
existing conveyances
Infiltration up to
1-yr, 24-hr storm
Diffuse flow in excess of
1-yr, 24-hr storm
*These controls apply within ½ mile and draining to these waters.
**Amount of Runoff that would need to be controlled in inches for the difference in pre- and post-development conditions for the
1-year, 24-hour storm.
For additional information on stormwater programs please go to http://h2o.enr.state.nc.us/su/
2007 Recommendations
DWQ recommends that the local governments develop programs that can go beyond the Phase II
six minimum measures. Implementation of Phase II, as well as the other stormwater programs,
should help to reduce future impacts to streams in the basin. Local governments, to the extent
possible, should identify sites for preservation or restoration. DWQ and other NCDENR
agencies will continue to provide information on funding sources and technical assistance to
support local government stormwater programs.
8.2.3 State Stormwater Program
The State Stormwater Management Program was established in the late 1980s under the
authority of the North Carolina Environmental Management Commission (EMC) and North
Carolina General Statute 143-214.7. This program, codified in 15A NCAC 2H .1000, affects
development activities that require either an Erosion and Sediment Control Plan (for disturbances
of one or more acres) or a CAMA major permit within one of the 20 coastal counties and/or
development draining to Outstanding Resource Waters (ORW) or High Quality Waters (HQW).
The State Stormwater Management Program requires new developments to protect these
sensitive waters by maintaining a low density of impervious surfaces, maintaining vegetative
setbacks, and transporting runoff through vegetative conveyances. Low density development
thresholds vary from 12-30 percent built-upon area (impervious surface) depending on the
classification of the receiving stream. If low density design criteria cannot be met, then high
density development requires the installation of structural best management practices (BMPs) to
collect and treat stormwater runoff from the project. High density BMPs must control the runoff
Chapter 8 – Stormwater and Wastewater Programs 125
from the 1 or 1.5-inch storm event (depending on the receiving stream classification) and remove
85 percent or 90 percent of the total suspended solids.
Current Status
Table 17 shows the 5 counties in the Little Tennessee River basin where permits may be required
under the state stormwater management program.
2007 Recommendations
DWQ will continue implementing the state stormwater program with the other NCDENR
agencies and local governments. Local governments should develop local land use plans that
minimize impervious surfaces in sensitive areas. Communities should integrate state stormwater
program requirements, to the extent possible, with other stormwater programs in order to be
more efficient and gain the most water quality benefits for protection of public health and aquatic
life.
8.3 Water Supply Watershed Stormwater Rules
Current Status
The purpose of the Water Supply Watershed Protection Program is to provide a proactive
drinking water supply protection program for communities. Local governments administer the
program based on state minimum requirements. There are restrictions on wastewater discharges,
development, landfills and residual application sites to control the impacts of point and nonpoint
sources of pollution. The program attempts to minimize the impacts of stormwater runoff by
utilizing low-density development or stormwater treatment in high-density areas.
All communities in the Little Tennessee River basin in water supply watersheds have EMC
approved water supply watershed protection ordinances.
2007 Recommendations
DWQ recommends continued implementation of local water supply protection ordinances to
ensure safe and economical treatment of drinking water. Communities should also integrate
water supply protection ordinances with other stormwater programs, to the extent possible, in
order to be more efficient and gain the most water quality benefits for both drinking water and
aquatic life.
126 Chapter 8 – Stormwater and Wastewater Programs
Table 17 Communities in the Little Tennessee River Basin Subject to Stormwater
Requirements
Local Government
NPDES
Phase I and Phase II
State Stormwater
Program
Water Supply Watershed
Stormwater Requirements
Municipalities
Bryson City
Dillsboro
Forest Hill
Franklin
Highlands X
Robbinsville X
Santeetlah
Sylva
Webster
Counties
Cherokee X
Clay X X
Graham X X
Jackson X X
Macon X X
Swain X X
8.3.1 Septic Systems and Straight Piping
In the Little Tennessee River basin, wastewater from many households is not treated at
wastewater treatment plants associated with NPDES discharge permits. Instead, it is treated on-
site through the use of permitted septic systems. Wastewater from some of these homes illegally
discharges directly to streams through what is known as a "straight pipe". In other cases,
wastewater from failing septic systems makes its way to streams or contaminates groundwater.
Straight piping and failing septic systems are illegal discharges of wastewater into waters of the
State.
With on-site septic systems, the septic tank unit treats some wastes, and the drainfield associated
with the septic tank provides further treatment and filtration of the pollutants and pathogens
found in wastewater. A septic system that is operating properly does not discharge untreated
wastewater to streams and lakes or to the ground’s surface where it can run into nearby surface
waters. Septic systems are a safe and effective long-term method for treating wastewater if they
are sited, sized and maintained properly. If the tank or drainfield are improperly located or
constructed, or the systems are not maintained, nearby wells and surface waters may become
contaminated, causing potential risks to human health. Septic tanks must be properly installed
and maintained to ensure they function properly over the life of the system. Information about
the proper installation and maintenance of septic tanks can be obtained by calling the
Chapter 8 – Stormwater and Wastewater Programs 127
environmental health sections of the local county health departments. See Appendix VII for
contact information.
The discharge of untreated or partially treated sewage can be extremely harmful to humans and
the aquatic environment. Pollutants from illegally discharged household wastewater contain
chemical nutrients, disease pathogens and endocrine disrupting chemicals. Although DWQ
ambient monitoring of the waters in the Little Tennessee basin show a relatively small
percentage of fecal coliform bacteria samples exceeding state standards for primary recreation,
volunteer monitoring in smaller streams shows a higher concentration of bacteria and other
pollutants. The economies of the counties in this basin are highly dependent upon river
recreation, especially for tourists and seasonal residents. Reducing bacterial contamination is
crucial for supporting a tourist economy.
In order to protect human health and maintain water quality, straight pipes must be eliminated
and failing septic systems should be repaired. The NC Wastewater Discharge Elimination
(WaDE) Program is actively helping to identify and remove straight pipes (and failing septic
systems) in the western portion of North Carolina. This program uses door-to-door surveys to
locate straight pipes and failing septic systems, and offers deferred loans or grants to
homeowners who have to eliminate the straight pipes by installing a septic system.
2007 Recommendations
The WaDE Program in collaboration with the Local Health Departments should request
additional funding from the CWMTF and Section 319 Program to continue the straight pipe
elimination program for the Little Tennessee basin. Additional monitoring of fecal coliform
throughout tributary watersheds where straight pipes and failing septic systems are a potential
problem should be conducted in order to narrow the focus of the surveys. For more information
on the WaDE Program, contact the DENR On-Site Wastewater Section (OSWW), NC Division
of Environmental Health, toll free at 1-866-223-5718 or visit their website at
http://www.deh.enr.state.nc.us/oww/Wade/wade.htm.
Additionally, precautions should be taken by local septic system permitting authorities to ensure
that new systems are sited and constructed properly and that an adequate repair area is also
available. Educational information should also be provided to new septic system owners
regarding the maintenance of these systems over time. DWQ has developed a booklet that
discusses actions individuals can take to reduce stormwater runoff and improve stormwater
quality entitled Improving Water Quality In Your Own Backyard. The publication includes a
discussion about septic system maintenance and offers other sources of information. To obtain a
free copy, call (919) 733-5083. The following website also offers good information in three easy
to follow steps: http://www.wsg.washington.edu/outreach/mas/water_quality/septicsense/septicmain.html.
128 Chapter 8 – Stormwater and Wastewater Programs