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Article 6: Development Standards39 <br /> Section 6.14: Stormwater Management <br /> (4) New development that would exceed the nutrient loading rates set out herein, <br /> shall include engineered stormwater controls designed to have a Primary and/or <br /> Secondary SCM per NCDEQ requirements. <br /> (5) Proposed new development may satisfy the review criteria standards of this <br /> section using a Runoff Volume Match design approach (also referred to as a Low <br /> Impact Development(LID) design approach) in conformance with 15A NCAC <br /> 02H.1002 (44). If pursued, a Runoff Volume Match design approach must <br /> include the use of the accounting methodologies approved by the North Carolina <br /> Division of Energy, Mineral, and Land Resources (NCDEMLR). <br /> (B) Additional Standards— Falls Lake Watershed <br /> (1) In addition to the standards contained in Section 6.14.6 (A) of this Ordinance, <br /> development shall observe a no net increase in peak flow leaving the site from <br /> predevelopment conditions for the 1 year, 24 hour, storm. <br /> (2) Proposed new development using a Runoff Volume Match design approach for <br /> satisfying stormwater management requirements must also include the <br /> estimation of pre-development and post-development nutrient export rates (e.g. <br /> Nitrogen and Phosphorous)for the proposed development, using the nutrient <br /> accounting methodologies approved by the North Carolina Division of Water <br /> Resources (NCDWR). Nutrient export estimates are required for Runoff Volume <br /> Match record-keeping purposes. <br /> 6.14.7 Nutrient Load <br /> (A) Nitrogen and phosphorus loads contributed by proposed new development shall not <br /> exceed the following unit-area mass loading rates: <br /> (1) Falls Lake Watershed <br /> (a) Nitrogen, 2.2 pounds per acre per year <br /> (b) Phosphorus, 0.33 pounds per acre per year <br /> (B) The nutrient export from each new development shall be calculated in pounds per acre <br /> per year(using the approved accounting tool) in accordance with the methodologies <br /> approved by the North Carolina Division of Water Resources (NCDWR). <br /> (C) If a proposed development subject to nutrient load requirements contributes nutrients <br /> greater than the standards listed above, the developer may install SCMs to meet the <br /> required nutrient load standards or do a combination of SCMs and offset payments to <br /> achieve the standard. <br /> (D) Offset Payments <br /> (1) Offset fees may be permitted to meet the nutrient export levels set for new <br /> development. In order to utilize offset fees, the proposed new development <br /> subject to the nutrient load standards must attain nitrogen and phosphorus <br /> loading rate reductions on-site that meet the following criteria prior to using an <br /> offsite offset measure: <br /> (a) Falls Lake Watershed <br /> (i) 30% or more reduction in both nitrogen and phosphorus loading <br /> from the untreated conditions for any single-family, detached and <br /> duplex residential development disturbing one half acre but less <br /> than one acre; <br /> (ii) 50% or more reduction in both nitrogen and phosphorus loading <br /> from the untreated conditions for any single-family, detached and <br /> duplex residential development disturbing more than one acre; <br /> (iii) 30% or more reduction in both nitrogen and phosphorus loading <br /> from the untreated condition for other development, including <br /> Orange County, North Carolina—Unified Development Ordinance Page 6-99 <br />