NDSD

Monetary	Relatively low cost when compared to no-action alternative (~$15 million)
Implementation	UPDES permitting; ongoing evaluations of potential impacts to water quality evaluations; Section 404 Individual Permit; coordination of work with Antelope Island State Park and Division of State Lands
Environmental Benefit	Effluent remains in GSL; New effluent-dominated wetland and bird habitat is formed but hydrology is changed on the mudflat at low GSL water levels
Public Perception	NDSD effluent continues to flow to GSL
Operation & Maintenance	Low maintenance associated with gravity pipeline and outfall, phragmites control downstream of the new outfall will be required
Regulatory Risk	Avoids regulatory uncertainty in Farmington Bay; some risk that new effluent limits may be required for Ogden Spur if HABs form

The Great Salt Lake and Environment

The table reflects potential benefits and impacts for GSL water levels of both above and below 4,195 feet.
Maintains Flow to GSL	Maintains flow to GSL
HAB Risk	Salinities > 5%, Negligible HAB Risk
Potential TP Accumulation	Full lake mixing, negligible risk of TP accumulation
Mudflat Hydrology	Reduction in flow to Farmington Bay mudflats. Increase inflow to Ogden Spur mudflats.
Bird Habitat	Gains/losses are generally offset by relocation.
Phragmites	Existing phragmites in Farmington Bay will decline without effluent. NDSD will control phragmites at the new location in Gilbert Bay.
Alternative No. 1—Outfall 002, GSL Water Levels < 4,195 feet
Maintains Flow to GSL	Maintains flow to GSL
HAB Risk	Salinities are potentially < 5%, Risk of HABs
Alternative No. 1—New Outfall 002, GSL Water Levels > 4,195 feet
Potential TP Accumulation	Potential for TP accumulation in Ogden Spur if GSL stays below 4,195 feet
Mudflat Hydrology	Reduction in flow to Farmington Bay mudflats. Increase inflow to Ogden Spur mudflats.
Bird Habitat	Likely significant net increase in bird habitat
Phragmites	Existing phragmites in Farmington Bay will decline without effluent. NDSD will control phragmites at the new location in Gilbert Bay.