HomeMy WebLinkAboutORD-2006-028 - Amendments to the Orange County Stormwater Ordinance for Lands within the Neuse River Basin0Alfj--�06� - V;L�l 1
ORANGE COUNTY
BOARD OF COMMISSIONERS
ACTION AGENDA ITEM ABSTRACT
Meeting Date: June 27, 2006
Action Agenda
Item No. -�2
SUBJECT: Amendments to the Orange County Stormwater Ordinance for Lands within the
Neuse River Basin
DEPARTMENT: Planning and Inspections PUBLIC HEARING: (YIN) No
ATTACHMENT(S): INFORMATION CONTACT:
1. Required Amendments to Orange County Craig Benedict, Planning Director, 245 -2592
Stormwater Ordinance Ren Ivins, Erosion Control Supervisor, 245-
2586
PURPOSE: To incorporate amendments in the Orange County Stormwater Ordinance to
conform to requirements of the North Carolina Department of Environment and Natural
Resources (DENR) for counties within the Neuse and Tar - Pamlico River Basins.
BACKGROUND: To protect water quality at the local level and provide a higher level of service
to citizens and clients, Orange County adopted the State's model stormwater ordinance in
March 2001. The title of the ordinance as adopted is, "Stormwater Ordinance for Lands within
the Neuse River Basin ". The Neuse basin covers most of northern Orange County including the
Town of Hillsborough. The Neuse Basin does not include the Chapel Hill /Carrboro area which
lies in the Cape Fear River Basin.
Hillsborough, which is now under a NPDES Phase II permit, is required to take additional
actions as its permit action plan identifies. Orange County Sedimentation and Erosion Control
is contracted to help the Town of Hillsborough in many aspects. In year three of the project, the
Town of Hillsborough has planned to include "Nutrient Export Reduction Options ", but it may
request that it be implemented earlier as part of the annual contract work plan.
Control of nitrogen runoff, or export, from development projects is a key feature of the program.
The Stormwater Ordinance provides Nutrient Export Reduction Options for residential or
commercial development contributing more than 3.6 Ibs /ac/yr of nitrogen. The options include
installation of best management practices (BMPs); a one -time offset payment of $330 /lb; or a
combination of BMPs and offset payments. Recognizing that costs do not remain static, the
State removed the $330.one -time payment (effective March 1, 2006) and inserted a nitrogen
offset payment formula to be adjusted annually based on the construction cost index factor
published each December in the Engineering News Record. Additionally, the name of the
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program to which offset payments are directed was changed from the Wetlands Restoration
Program (WRP) to the North Carolina Ecosystem Enhancement Program ( NCEEP).
The Nutrient Export Reduction Options (NERO) part of the program is an aspect of the overall
land disturbance permit. The Erosion Control Division evaluates the design, verifies the NERO
method, and forwards the compensation payment to the DENR Division of Water Quality for
use in Orange County restoration projects as part of the NCEEP program. Presently, the
Erosion Control Division and Natural Resources Conservation Service (NRCS) staffs are
looking for sites to retrofit to improve water quality, manage peak flow, and ameliorate overall
erosion issues.
The amendments referenced above are contained in Attachment 1 with deletions shown in bel4
rtF° ' tr-G and additions in bold underline. Orange County's Stormwater Ordinance is
taken directly from the State's model ordinance and the amendments likewise originate at the
State level. Given the state -to -local transfer of amendments, staff does not envision the need
for a public hearing as would be the case with Orange County's zoning ordinance or subdivision
regulations.
FINANCIAL IMPACT: As the Board may recall, this overall stormwater program was delegated
to Orange County by the State. The program in Orange County's portion of the Neuse River
Basin is partially funded by developer fees. Existing Erosion control staff is currently
implementing and administering the program.
RECOMMENDATION(S): The Administration recommends incorporation of the amendments
into the Orange County Stormwater Ordinance for Lands within the Neuse River Basin
consistent with State requirements.
3
Amendments to the Orange County
Stormwater Ordinance
April 2006
NOTE: The underlined text will be added to the Ordinance and the struck - through text
will be deleted. The attached Stormwater Ordinance amendments conform to
requirements by the North Carolina Department of Environment and Natural Resources
made effective as of March 1, 2006 for counties within the Neuse and Tar - Pamlico River
Basins.
Section 6 Nutrient Load Calculations
For the purpose of this Ordinance new development shall be defined by as to include the
following:
Any activity that disturbs greater than one acre of land in order to
establish, expand or modify a single family or duplex residential
development or a recreational facility.
Any activity that disturbs greater than one -half an acre of land in order to
establish, expand, or modify a multifamily residential development or a
commercial, industrial or institutional facility.
New development shall not include agriculture, mining, or forestry activities. Land
disturbing activity is defined as grubbing, stump removal, and/or grading.
A. The nitrogen export from each new development must be calculated. This
export will be calculated in pounds per acre per year (lbs /ac /yr). The two
methodologies that are to be used are as follows.
1. Method 1
This method is intended for use where lots are shown but the actual
footprint of buildings are not shown on site plans. This method does not
require calculation of the area of building footprints. Rather, the
impervious surface resulting from building footprints is estimated based
on typical impervious areas associated with a given lot size. This method
is shown in Appendix 1.
2. Method 2
This method is for residential, commercial, and industrial development
when the entire footprint of the roads, parking lots, buildings, and any
other built -upon area is shown on the site plans. This method is simpler
and more accurate since it does not require estimating the impervious
surface based on lot size. Method 2 is shown in Appendix 2.
a) If a non - residential subdivision plan is submitted without
impervious surfaces not shown, the following two options are
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available:
(1) Option A
Property owner must specify the areas of impervious
surface, undisturbed open space and managed open space
on the property in a restrictive covenant. Method 2 would
then be applied.
(2) Option B
Planning staff will determine a worst -case scenario for the
areas of impervious surface and managed open space for
the type of development specified. Method 2 would then be
applied.
B. Nutrient Export Figures
Calculations must be in accordance with either Method 1 or 2 shown in Appendix
1 and 2, respectively, of this Ordinance.
C. Nutrient Export Reduction Options
If calculations show that the development will contribute greater than 3.61bs /ac /yr
of nitrogen, then the options shown below are available.
1. Residential Development
a) If the calculated nitrogen export is less than 6.0 lbs /ac /yr, then
the owner may:
(1) Install BMPs specified in Section 8 to reduce nitrogen
export amounts to 3.61bs/ac /yr.
(2) Pay a one -time offset payment o f Q� 2 04b. This offset
fee will go to the
North Carolina Ecosystem Enhancement Program
(NCEEP). The MIRP- NCEEP will utilize these fees in
accordance with the Basinwide Wetlands and Riparian
Restoration plans. It is the policy of the Mqlp NCEEP to
utilize the funds where they are generated to the maximum
extent possible.
(3) A combination of BMPs and offset payments may be
used to achieve 3.61bs /ac /yr.
b) If the calculated export is greater than 6.0 lbs /ac /yr, the owner
must use on -site BMPs to lower the nitrogen export to 6.0
lbs /ac /yr. The owner may then use one of the above options to
achieve a nitrogen export level of 3.6 lbs/ac /yr.
2. Commercial and Industrial
a) If the calculated export is less than 10.0 lbs /ac /yr, then the
owner may:
(1) Install BMPs specified in Section 8 to reduce nitrogen
n
export amounts to 3.61bs/ac /yr.
(2) Pay a one -time offset payment -e€ 3304h. This offset
fee will go to the `xledaBds Rester- do Program OAW)
North Carolina Ecosystem Enhancement Program
(NCEEP). The )AW NCEEP will utilize these fees in
accordance with the Basinwide Wetlands and Riparian
Restoration plans. It is the policy of the WRP NCEEP to
utilize the funds where they are generated to the maximum
extent possible.
(3) A combination of BMPs and offset payments may be
used to achieve 3.6 lbs /ac /yr.
b) If the calculated export is greater than 10.0 lbs /ac /yr, the owner
must use BMPs to lower the nitrogen export to 10.0 lbs /ac /yr. The
owner may then use one of the above options to achieve a nitrogen
export level of 3.61bs /ac /yr.
D. Calculating Peak Runoff Volume
For all new development, there shall be no net increase in peak flow leaving the
site from the predevelopment conditions for the 1 year, 24 hour storm.
1. The following are acceptable methodologies for computing the pre -
and post- development conditions for the 1 year, 24 hour storm.
a) Rational Method
b) Peak Discharge Method as described in the USDA Soil
Conservation Service's Technical Release Number 55 (TR -55).
c) Putnam Method
d) Alternative methods must be approved by the County and the
EMC
2. The same method must be used for both the pre- and post -
development conditions.
3. Raleigh Rainfall Depths
a) 1 year, 24 hour depth: 3.00 inches
b) 1 year, 24 hour intensity: under development by DWQ staff
E. Exemptions to the Peak Flow Requirements
Peak flow requirements are waived for development that meets the following
criteria:
1. Increase in peak flow between pre- and post- development conditions
does not exceed 10% (ten percent).
2. Proposed new development meets all of the following criteria:
a) total impervious surface is less than 15% (fifteen percent), and
b) remaining pervious surface maximizes stormwater runoff
control and conveyance.
3. Detention will cause further flooding on lands that have experience
5
G
flooding during previous storm events. This request for exemption must be
prepared by a North Carolina registered professional engineer and
submitted in writing to the Planning Director or Designee. Appeals of this
decision will follow Section 7 -E of this Ordinance.
Appendix 2
Table 2a: Nitrogen Export Reduction Options
Residential
Commercial / Industrial
If the computed export is less than 6.0
If the computed export is less than 10.0
lbs/ac /yr, then the owner may either:
lbs/ac /yr, then the owner may either:
1. Install BMPs to remove enough nitrogen
1. Install BMPs to remove enough nitrogen to
to bring the development down to 3.6
bring the development down to 3.6
lbs/ac/yr.
lbs/ac/yr.
2. Pay a one -time offset payment of S330A
2. Pay a one -time offset payment of $33OAb
to bring the nitrogen down to the 3.6
to bring the nitrogen down to the 3.6
lbs/ac/yr.
lbs/ac/yr.
3. Do a combination of BMPs and offset
3. Do a combination of BMPs and offset
payment to achieve a 3.6 lbs /ac /yr export.
payment to achieve a 3.6 lbs/ac/yr export.
If the computed export is greater than 6.0
If the computed export is greater than 10.0
lbs/ac /yr, then the owner must use on -site
lbs/ac/yr, then the owner must use on -site
BMPs to bring the development's export
BMPs to bring the development's export down
down to 6.0 lbs/ac /yr. Then, the owner may
to 10.0 lbs/ac /yr. Then, the owner may use one
use one of the three options above to achieve
of the three options above to achieve the
the reduction between 6.0 and 3.6 lbs/ac/yr.
reduction between 10.0 and 3.6 lbs/ac/yr.
The table above discusses the option of using offset fees to meet the nitrogen export
levels set for new development activities. These offset fees go to the N.C. Ecosystem
Enhancement Program (NCEEP). The
EEP- NCEEP will utilize these fees in accordance with the Basinwide Wetlands and
Riparian Restoration plans. It is the policy of the FXP NCEEP to utilize the funds where
they are generated to the maximum extent possible as long as they can obtain the
cooperation of the local government.
To calculate the total amount of offset payment, use the following formula:
R�.•...z �:,,
o
C
*Nitrogen Offset Payment = i ($57 / IN x (# of lbs / year) x (30 years)
+ (Land Cost $ / Ac) x (1 Ac / 35 Ac)
x (bevel. in Ac)1 x (1.1 Ad Costs)
*This factor will be adiusted annually based upon the construction cost index
factor published each December in the Engineering News Record.
Where: lbs / year represents the amount of nutrient exported or discharged per year
for which mitigation is being requested; Land Cost $ / Ac represents current
Property value in dollars per acre of the property being developed, based on the
most recent tax assessment; 1 Ac / 35 Ac represents an adiustment factor indicating
that one acre of mitigation is required for every 35 acres of development and 1.1 Ad
Costs represents an adiustment factor to cover administrative cost associated with
the requested mitigation.
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dd. Eno Economic Development District (EDD) Small Area Plan e �'-
This item was removed and placed at the end of the consent agenda for separate
consideration.
ee. Amendments to the Orange County Stormwater Ordinance for Lands within the
Neuse River Basin
The Board incorporated amendments in the Orange County Stormwater Ordinance to
conform to requirements of the North Carolina Department of Environment and Natural
Resources (DENR) for counties within the Neuse and Tar - Pamlico River Basins.
ff. Approval of Proposed Lease Agreement with OPC at Northside
This item was removed and placed at the end of the consent agenda for separate
consideration.
gg.Authorization to Release One -Time Supplemental Funding to OPC /LME to
Facilitate Divestiture of Orange County Outpatient Services
The Board authorized the release of a one -time County supplemental appropriation in the
amount of $131,797 to OPC /LME to facilitate the divestiture (transfer) of the Northside Adult
and Child Outpatient Clinics in Chapel Hill and the Family Counseling Center in Hillsborough
services to the Caring Family Networks (CFN) and authorized the County Finance Director to
release the funds to OPC in anticipation of the requisite budget amendment.
hh. Budget Amendment #17
This item was removed and placed at the end of the consent agenda for separate
consideration.
ii. Adoption of Resolution Authorizing OPC /LME to Acquire Real Property in Orange
County
The Board adopted a resolution, which is incorporated by reference, that provides consent
for the OPC /LME to enter into a financing agreement for the acquisition of real property.
fL Approval to Enter into a Proposed Contract with The Town of Carrboro for Interim
Provision of Limited Animal Control Services
The Board approved a County response to a request from the Town of Carrboro to provide
limited Animal Control Services within the Town for a period beginning June 19, 2006 and
ending no later than October 1, 2006. Final approval of the County's proposed agreement for
interim provision of select service will depend upon formal acceptance by the Town of Carrboro.
VOTE ON CONSENT AGENDA: UNANIMOUS
ITEMS REMOVED FROM CONSENT AGENDA:
W. Boards County Commissioners Serve On
The Board considered the list of boards and commissions on which the Board of County
Commissioners members serve and selected those boards on which the BOCC wishes to
continue serving.
Commissioner Gordon said that she would be willing to serve as the Board liaison for
the Advisory Board on Aging, the Rural Planning Organization as a member (starting in
October), and the alternate for the Space Needs Study Group.
A motion was made by Commissioner Gordon, seconded by Commissioner Halkiotis to
approve the list of boards and commissions on which the Board of County Commissioners
members serve with the proposed changes.
VOTE: UNANIMOUS