20090197 Ver 1_More Info Received_20090403

Sa/isbury-R?wan
O"h'E C_ F,, I V rm D
MEMORANDUM
TO: NCDENR Mooresville Regional Office
610 East Center Avenue
Mooresville, NC 28115
Attn: Mr. Alan Johnson
FROM: Chris Tester, Utilities Engineer
DATE: April 1, 2009
APR - IF
?n

DM-Surface
SUBJECT: 401 Water Quality Certification DWQ#09-0197, written comments to
address cumulative impacts for SRU 2007 Annexation Sewerline.
Please find the attached documentation:
One (1) set of written comments addressing item #1 of the approved 401 Water Quality
Certification.
One (1) copy of approved 401 Water Quality Certification.
Ow4, Tester, EI
Salisbury-Rowan Utilities
[phone] (Office)
[phone] (Cell)
[phone] (Fax)
Email: [e-mail]
1 Water Street Telephone [phone]
Salisbury, NC 28144 Salisbury-Rowan Utilities Fax [phone]
Salisbury - Rowan Utilities (SRU) is preparing this summary to address your request of
24 March 2009, included in our 401 Water Quality Certification Approval letter (DWQ #
09-0197), to provide a Cumulative Impact Analysis. We share the Division's concerns
with regard to future development under our pervue and are pleased to share the below
details of our programs. Portions of our service area lie within the jurisdictions of both
Rowan County and the City of Salisbury. As such, we have included details of each
government's regulations to address your concerns.
Rowan County and the City of Salisbury employ a variety of measures to avoid,
minimize, and compensate for the adverse impacts of urban development and other land
use changes induced or supported by expanded public utility service. These include
land use planning, zoning, and permitting tools, low-impact development incentives,
water supply watershed regulations, stream buffer and floodplain development
restrictions, stormwater management requirements, drought management program, park
land acquisition, coordination with the DENR regional office, utility companies, and local
land trusts, and other regulatory and non-regulatory activities. Below we discuss some
of he pertinent measures, and invite you to review the entire text of these regulations
found in our recently adopted Land Development Ordinance, available on our website;
http://www.salisbu[ync.gov/lm&d/zoning/intro.htmi. Chapter 9 of this document outlines
the Environmental Protections we have put in place to address the Secondary and
Cumulative Impact concerns of a variety of projects.
City of Salisbury
Land Use Impacts
The City of Salisbury requires that adequate storm drainage systems be designed and
approved prior to the issuance of a zoning permit. Developers are encouraged to utilize
existing storm water collection facilities if available, rather than creating a new
stormwater discharge to surface waters.
Where a subdivision is traversed by a watercourse, drainageway, channel, or stream, a
storm water easement conforming with the lines of such watercourse must be provided.
Lakes, ponds, creeks, and similar areas within the city will be accepted for maintenance
only if sufficient land is dedicated as a neighborhood recreation area or park.
The proposed subdivision of any property located partially or entirely within a WS-IV-PA
(Watershed) Overlay must be approved by the zoning board of adjustment for
conformance with the watershed ordinance.
Preliminary subdivision plats shall show wooded areas, marshes, buffer areas, floodplain
information, National Register of Historic Places designation, or any other conditions
affecting the site.
Stormwater
The City of Salisbury is an NPDES Phase II Community. Pursuant to its requirements
under this designation, Salisbury requires that projects maintain the pre- and post-
construction hydrographic conditions as nearly as practicable to reduce flooding,
streambank erosion, point and non-point pollution, in-stream temperature fluctuations,
and the integrity of stream habitats. Qualifying projects must provide post-construction
stormwater controls through structural or non-structural BMPs, and provide assurances
that those BMPs will be maintained in perpetuity.
Projects proposing to impact one acre or more of land are required to secure a
stormwater permit prior to construction. Low density projects (those with no more than
two dwelling units per acre or 24% imperviousness) require all built upon area to be a
minimum of 30-feet landward of all intermittent and perennial surface waters as shown
on Soil Survey or USGS topographic quadrangle mapping. High Density projects (those
that exceed the Low Density criteria listed above) are required to treat the difference in
stormwater runoff volume leaving the property between the pre- and post-development
condition for, at a minimum, the 1-year 24-hour storm. Stormwater treatement facilities
must be designed to remove a minimum of 85% TSS, and drawdown time must be at
least 24 hours. All built upon area to be a minimum of 30-feet landward of all intermittent
and perennial surface waters as shown on Soil Survey or USGS topographic quadrangle
mapping.
Floodplain Impacts
The areas of special flood hazard are identified by the Federal Emergency Management
Agency in its flood insurance study for the City of Salisbury, dated November, 1979, with
accompanying flood insurance rate maps, flood boundary and floodway maps, effective
date of May 15, 1980, as well as any revisions thereto.
All subdivision proposals shall have adequate drainage systems provided to reduce
exposure to flood hazards. Applications for development permits within the special flood
hazard areas must contain a plan that shows the 1) The 100-year floodplain contour or a
statement that the entire lot is within the floodplain, and 2) The floodway (if any). Where
base flood elevation data is provided on FEMA mapping, the application shall show the
elevation of the lowest floor of all new and substantially improved structures, and If the
structure has been floodproofed, the elevation to which the structure was floodproofed.
Where the base flood elevation data is not provided, the application must show
construction of the lowest floor at least two (2) feet above the highest adjacent grade.
Where any watercourse will be altered or relocated, the application shall include: a
description of the extent of watercourse alteration or relocation; an engineering report on
the effects of the proposed project on the flood-carrying capacity of the watercourse and
the effects to properties located both upstream and downstream; and a map showing the
location of the proposed watercourse alteration or relocation.
All new and replacement water supply and sewage collection systems shall be designed
to minimize or eliminate infiltration of floodwaters into the systems and discharges from
the systems into floodwaters. On-site waste disposal systems shall be located and
constructed to avoid impairment to them or contamination from them during flooding.
public utilities and facilities such as sewer, gas, electrical and water systems located and
constructed to minimize flood damage.
New construction or substantial improvement of any structures shall have the lowest
floor, including basement, elevated no lower than one foot above the level of the base
flood elevation. Commercial, Industrial and other non-residential structures located in A-
zones may be floodproofed in lieu of elevation.
An evacuation plan must be developed for all residents of new, substantially improved or
substantially damaged manufactured home parks or subdivisions located within flood
prone areas. This plan shall be filed with and approved by the local administrator and the
local emergency management coordinator.
No encroachments, including fill material or structures shall be located within a
designated floodway until an engineering report which shows the affect on the base
flood elevation is approved by the administrator
Wetiands and vvaiers impacis
The City of Salisbury enforces four levels of water shortage responses, from voluntary
measures to mandatory restrictions. Depending on the severity of the emergency,
voluntary (level 1), mandatory (level 1), mandatory (level II), mandatory (level III) or
mandatory (level IV) staged water use restrictions as described in this article shall be
imposed upon water customers.
Level one restrictions are voluntary and include minimizing irrigation and washing
machine and dishwasher use, defer filling of swimming pools, etc. Levels two, three,
and four are mandatory, and progressively stricter restrictions on potable water use.
During a level four water restriction, large-scale commercial and industrial water
customers utilizing 5,000 or more gallons of water per day shall achieve mandatory
reductions in daily water usage through whatever means are available. All use of water
for purposes other than maintenance of public health and safety are prohibited.
Water Quality Impacts
Each industrial user of the sanitary sewer system shall provide protection from
accidental discharge of prohibited materials or other wastes, and prepare an accidental
spill prevention program.
Rowan County
Stormwater
Subdividers are required to provide surface water drainage systems constructed to the
standards of the North Carolina Department of Transportation, as reflected in "Handbook
for the Design of Highway Surface Drainage Structures," 1975. The subdivider shall
connect to an existing storm drainage system wherever one is existing. Surface
drainage courses shall be of sufficient size to accommodate the drainage area without
flooding. Stream banks and channels downstream shall be protected from increased
degradation by accelerated erosion caused by increased velocity of runoff from land
disturbing activities. In areas of special flood hazards, all subdivision proposals shall
have adequate drainage provided to reduce exposure to flood damage.
Rowan County requres stromwater control plans for all projects that disturb one acre or
more. Plans are requred to: identify critical areas (those areas both on and off-site that
are subject to severe erosion); limit the time and area of exposure, control surface water
and erosion, and manage stormwater runoff from the site. Protection from stormwater
from the peak rate of runoff from the ten-year storm shall be provided onsite, except in
HQW zones where protection from the 25-year storm peak flows shall be provided.
Vegetated buffers of sufficient width to confine visible siltation to within the landward
25% of the buffer are requried adjacent to all lakes and natural watercourses.
Floodplain Protection
The "areas of special flood hazard" are those identified by the Federal Emergency
/rr-A / n :a_ t?_ _ I 1 J 1 J r 41-^ J i rn rare a4w
Nlanagen ient Agency ?rclvlr%) Ii1I IL6 uvvu I I0Za1 U LVUI Juai Y I i ICIP v1 111Jv?a ii I?Mi u4
and flood insurance rate maps, for Rowan County dated November 1, 1979.
Proposals for subdivisions and major developments shall be consistent with the need to
minimize flood damage, shall have public utilities and facilities located and constructed
to minimize flood damage, and have adequate drainage provided to reduce exposure to
flood hazards. No encroachments, including fill, new construction, substantial
improvements or new development shall be permitted within a distance of twenty feet
each side from top of bank or five times the width of the stream whichever is greater.
Application for development requires a plan that shows the one-hundred-year floodplain
contour or a statement that the entire lot is within the floodplain, and the floodway as
identified by the Federal Emergency Management Agency. Where base flood elevation
data is provided the application shall show the elevation of the lowest floor of all new and
substantially improved structures. If a nonresidential structure will be floodproofed, the
application shall show the elevation to which the structure will be floodproofed.
Where the base flood elevation data is not provided, the lowest floor shall be at least
four feet above the highest adjacent grade. Where any watercourse will be altered or
relocated as a result of proposed development, the application for a development permit
shall include: a description of the extent of watercourse alteration or relocation; an
engineering report on the effects of the proposed project on the flood-carrying capacity
of the watercourse and the effects to properties located both upstream and downstream.
All new and replacement water supply systems shall be designed to minimize or
eliminate infiltration of flood waters into the system, and new and replacement sanitary
sewage systems shall be designed to minimize or eliminate infiltration of flood waters
into the systems and discharges from the systems into flood waters. On-site waste
disposal systems shall be located and constructed to avoid impairment to them or
contamination from them during flooding.
New construction or substantial improvement of any structure shall have the lowest floor,
including basement, elevated no lower than four feet above the base flood elevation.
Non-residential structures located in A Zones may be floodproofed to the flood protection
level in lieu of elevation.
An evacuation plan must be developed for evacuation of all residents of all new,
substantially improved or substantially damaged manufactured home parks or
subdivisions located within flood prone areas.
Buffers
Within water supply watersheds, a minimum 30-foot vegetative buffer for development
activities is required along all perennial waters indicated on the most recent versions of
U.S.G.S. 1:24,000 (7.5 minute) scale topographic maps. The retention of existing
vegetation shall be maximized to the extent practical.
Water Quality Impacts
The County regulates certain land-disturbing activities to control accelerated erosion and
sedimentation in order to prevent the pollution of water and other damage to lakes,
watercourses and other public and private property by sedimentation. Stormwater
control structures should include measures to promote infiltration to compensate for
increased runoff, use vegetated or roughened swales and waterways in lieu of closed
drains, provide energy dissipation at outlets of storm drainage facilities, and protect
watercourses by improving cross sections and/or providing erosion resistant lining. With
the exception of certain regulated mining, farming, and silvicultural activities, the
following provisions are required within the jurisdiction of Rowan County.
No person shall initiate any land-disturbing activity which uncovers more than one acre
without having an erosion control plan approved by the county. An erosion and
sedimentation control plan may be disapproved if it fails to identify critical areas, limit
time of exposure, limit exposed areas, control surface water, control sedimentation, or
manage stormwater runoff. Slopes left exposed will, within 21 working days of
completion of any phase of grading, be planted or otherwise provided with ground cover,
devices or structures sufficient to restrain erosion.
No land-disturbing activity shall be permitted in proximity to a lake or natural watercourse
unless a buffer zone is provided along the margin of the watercourse of sufficient width
to confine visible siltation within the twenty-five percent of the buffer zone nearest the
land-disturbing activity.
Erosion and sedimentation control measures, structures and devices shall be designed
to provide protection from the peak runoff from the ten-year storm.
Uncovered areas in HQW zones shall be limited at any time to a maximum total area of
20 acres. Larger areas may be uncovered within the boundaries of the tract with the
written approval of the director. Erosion and sedimentation control measures within
HQW zones shall be designed to provide protection from the runoff of the twenty-five-
year storm. Sediment basins within HQW zones shall have a settling efficiency of at
least 70 percent for the forty-micron (0.04mm) size soil particle transported into the basin
by the runoff of that two-year storm. Newly constructed open channels in HQW zones
shall have side slopes no steeper than two horizontal to one vertical if a vegetative cover
is used for stabilization. Ground cover sufficient to restrain erosion must be provided
within fifteen working days or sixty calendar days following completion of construction or
development.
The post construction velocity of the ten-year storm runoff in the receiving watercourse
to the discharge point should not exceed the pre-development conditions. If this cannot
be met, then the receiving watercourse to and including the discharge point must be
designed and constructed to withstand the expected velocity anywhere the velocity
exceeds the pre-development velocity by ten percent.