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4a-8 TD1NN OF CHAPEL HILL STAFF D~MMENT AND C~UETIONs REGARDING PR~P~SED JORDAN LASE NUTR[ENT TI~ITEGY RULES - SUBMITTED E~TEMBBR ~, ~0~7 ~~A NCAC ~~B.D~G~: 1~IiAT~~S~Ei~ NL~TRI~NT REDU~T~~~ SAL 1. Rule .0262(3) states reduction goals are in terms of a percentage reduction in delivered nutrient Toads to the lake. What transport factors were used, i~ any, to determine how much of an individual site's nutrient load is delivered to the lake? Does this transport factor apply to both percentage reductions (as for existing development -see x.0266(3}(a)) and the unit-area mass loading rates has for new deveiapment -see §.a2fi5(3)(a)(i))? ~, Aerial deposition of nitrogen from local and distant combustion sources} i a significant contributor to nitrogen loads in araa water bodies. Aerially-deposited nitrogen as a nutrient source is addressed by the rules in .0~6~~8} only as an acknowledged limitation, and suggests the EMC could undertake separate rule-nuking in the future to support the Jordan Rules. Achieving success in reducing nitrogen loads to Jordan Lake may be highly dependent on addressing aerial sources, Urban impervious surfaces such as sidewalks and roofs typically do not produce nitrogen and phosphorus; they do collect dry particulates that get washed off during precipitation events. Addressing local combustion sources such as the heavy traffic in the Triangle and Triad regions is certainly feasible and has a variety of human health and enviranmenta] benefits. Ernissions control has worked very well in the past for controlling load pollution. Current methods for emissions contra] also offer carban~reduction benefits. Carbon reduction is a stated goal of both the Chapel Hiil Tawn Council and the University of North Carolina, and u~rill become increasingly adopted by other ~urisd[ctians as our climate chows signs of change. is it more cost-effective to be treating aerially-deposited nitrogen using stormwater management rather than limiting its creation through combustion sources? vUouldn't it be cheaper to central nitrogen ofi the source rather than try to treat it secondarily through stormwater management? Biosolids application is currently allowed in the Upper New Haile Arm subwatershed. vllhat is the estimated nutrient cantributian from this application? vUauld it be considered a fertiliser? inc~ bioolids application has the potential to be a significant nutrient source, it needs to be regulated as part of the Jordan [pules, in spite of the fact that it's already subject to existing regulatory and compliance programs. Those existing programs were not developed v~ith the gaa[ of vuatershed nutrient management. 4. There are no existing programs to control nutrient loads from onsite wastewater systems (e.g. septic systems}. Land uses with septic systems were considered #o contribute a large amount of nutrients in the Division of Water Qua[ifiy's reckoning of nutrient allocations by land use type. It is not clear if local ga~ernments have the authority to require regular inspections and/or maintenance ofi onsite wasfiewater systems or rnust rely on the county or state en~ironmentai health programs to enforce these provisions. 5. The Division of vlEater Quality held four stakeholder meetings to design an adaptive management plan for the lake. The results of this plan vuau[d revise the lake model to have more computational "ce[Is" t~ better model inylake processes. The plan would also add new lake rrxanitaring sites, and new watershed rnanitaring sites on small tributaries in the Laver New Hope Arm and in the Hain Arm of the lake to hotter estimate nutrient delivery loads. Na new sites uvould be added in the Upper Neva Hope Arne there are Page ~ of 9