Air Quality and Climate

• Under all alternatives, including Alternative A, fugitive dust, air pollutant, and greenhouse gas emissions would occur related to O&M activities. Emissions from O&M activities would be reduced under all action alternatives compared with Alternative A because less maintenance would be needed.

• Under all action alternatives, construction would generate temporary and localized fugitive dust, greenhouse gas emissions, and other air pollutants, which would be minimized using standard dust control and other BMPs. Contribution to global greenhouse gas emissions are expected to be well below the greenhouse gas reporting requirement threshold under 40 CFR 98.

• Alternative C would have the lowest emissions of the action alternatives because there would be less construction activity due to the shorter length of conveyance pipeline being replaced.

• Alternative D would have the highest emissions of the action alternatives because of the increased Phase I construction timeline and the need for additional pumping for the temporary Hatchery water supply.

Geology and Soils

• Under Alternative A, sediment from upstream sources would continue to be diverted from Icicle Creek to the Hatchery, and would be periodically removed and stored on-site.

• Under all action alternatives, construction would result in localized effects from ground disturbance and movement of geologic materials. BMPs to minimize surface disturbance, control erosion, and reclaim temporarily disturbed areas would reduce impacts.

• Alternative C would have the fewest effects of the action alternatives because there would be less construction activity due to the shorter length of conveyance pipeline being replaced.

Water Resources

• Under Alternative A, sediment would continue to be diverted from Icicle Creek, removing its contribution to stream geomorphology and stream conditions.

• Under all action alternatives, intake rehabilitation would greatly reduce sediment diversion, allowing it to remain in the creek and contribute to stream conditions. Surface disturbances from construction within the 100-year floodplain would occur. Surface disturbances and equipment use in and adjacent to Icicle Creek could result in contaminants (e.g., soil, lubricants, fuel, etc.) entering the creek and affecting water quality. BMPs and permit conditions would reduce impacts.

• Alternatives B and C would have the highest potential that prolonged precipitation or rain-on-snow events could overtop, dislodge, or destroy the cofferdam because there would be two weeks of cofferdam use during November.

• Of the action alternatives, Alternative D would have the lowest potential that prolonged precipitation or rain-on-snow events could overtop, dislodge, or destroy the cofferdam because cofferdams would be removed by October 31 each year. However, there would be two additional seasons of cofferdam use compared with Alternatives B and C, increasing potential for contaminants entering the creek and affecting water quality.

• Alternative C would remove the fewest shade-producing trees of the action alternatives because less conveyance pipeline would be replaced. As a result, effects from increased water temperature and lowered dissolved oxygen would be lowest.

Biological Resources

• Alternative A would not comply with current NMFS fish screening and passage criteria. The existing intake facilities result in the take of ESA-listed fish, and negatively impact fish passage and aquatic habitat quantity, quality, and connectivity

• All action alternatives would comply with current NMFS fish screening and passage criteria for anadromous salmonids and would reduce take of ESA-listed fish compared with current conditions. Construction would temporarily affect ESA-listed fish, critical habitat, and EFH, but BMPs and conservation measures incorporated or developed during ESA Section 7 consultation with the NMFS and USFWS would reduce effects.

• Under Alternative C, impacts on fish and aquatic habitat and vegetation would be reduced compared to Alternative B and D because less conveyance pipeline would be replaced, and fewer shade-producing trees would be removed.

• Under Alternative D, effects on fish and aquatic habitat would occur over a longer time frame, because the time needed to complete the Project would be longer. There would also be additional impacts from Phase I construction temporary Hatchery water supply pumping for a longer time period, inundation of the partially constructed intake headworks after cofferdam removal, and remobilization/demobilization efforts before and after each additional construction season.

• Under all action alternatives, effects on vegetation would be minor and effects on terrestrial wildlife species would be minor or negligible.

Land Use, Utilities, and Service Systems

• Under Alternative A, there would be no changes to current land uses, zoning, land ownership, entitlements, or existing utilities aside from routine maintenance or future improvements.

• Under all action alternatives, existing intake facilities and the conveyance pipeline would be modified, replaced, rehabilitated, and new intake elements would be constructed. There would be no change in the current land uses, zoning, landownership, or entitlements. Relocation of at least one power pole and minor upgrades to the overhead electrical infrastructure could result in a temporary lapse in electrical supply to area users.

Transportation and Traffic

• Under Alternative A, there would be no change in the Level of Service (LOS) in the Project Area. Traffic impacts associated with routine or extraordinary activities would continue.

• Under all action alternatives, heavy vehicle traffic using Icicle Road and Icicle Creek Road and the turnaround at the Forest Service and Alpine Lakes Wilderness kiosk would temporarily reduce the LOS in these areas. Traffic control BMPs would reduce effects.

• Under Alternative C, temporary reductions in LOS would be reduced, because there would be fewer heavy equipment vehicle trips accessing the intake construction area.

• Under Alternative D, temporary reductions in LOS would be reduced, because construction activities after 10:00 p.m. would not occur. However, impacts would be experienced over a total of four Phase I construction seasons instead of two.

Noise and Vibration

• Under Alternative A, there would be no new construction activity that would affect ambient noise levels. Occasional noise and vibration associated with current O&M activities of the intake facilities and conveyance pipeline would continue.

• Under all action alternatives, equipment and vehicle use associated with construction would raise ambient noise levels for sensitive receptors and increase vibration. Expected loudest noise levels would be generated by a pneumatic tool (Phase I construction) and hot air blower (Phase II construction).

• Under Alternatives B and C, increases in ambient noise levels could occur for up to 24 hours per day, and up to 7 days per week during Phase I construction. Additional lining of the conveyance pipeline with CIPP under Alternatives B and C would result in negligible differences in noise from use of the hot air blower during Phase II construction.

• Alternative C would require fewer truck trips to access the intake construction area, resulting in less construction noise for sensitive receptors along Icicle Road/Icicle Creek Road.

• Under Alternative D, daily noise impacts would be reduced over Alternatives B and C because there would be no Phase I construction work from 10:00 p.m. to 7:00 a.m. However, impacts would be experienced over a total of four Phase I construction seasons instead of two. Additionally, the two diesel pumps associated with the temporary Hatchery water supply for Phase I construction would operate 24 hours per day and 7 days per week for a period of 8 months, as opposed to approximately 10 days.

Recreation

• Under Alternative A, there would be no construction-related impacts to recreational conditions, opportunities, or access. More frequent maintenance activities may temporarily impact recreational conditions or access.

• Under all action alternatives, temporary impacts to recreational conditions and access would occur during construction, which may temporarily depress recreational visitation rates. Long-term benefits to recreational fishing would result from enhanced fish passage and aquatic ecosystem productivity.

• Under Alternative C, temporary impacts to recreational conditions and access would be reduced because there would be fewer delays from heavy equipment vehicle trips accessing the intake construction area.

• Under Alternative D, temporary impacts to recreational conditions and access would be reduced because there would be a shorter in-water work window. However, overall impacts to recreationists would be experienced over four Phase I construction seasons instead of two, including during the peak recreation season.

Visual Resources    

• Under Alternative A, visual quality would remain unchanged and there would be no additional impacts to the viewshed.

• Under all action alternatives, construction-related activities such as use of heavy machinery and warning signs would sharply contrast with the natural lines, form, and color within the existing viewshed, and construction noise, light, and level of the activity would draw the attention of the casual observer.

• Under Alternative C, impacts would be lowest of the action alternatives because there would be less construction-related activity due to lining a greater length of the conveyance pipeline. Also, disturbance in the Icicle Creek riparian zone would be reduced, reducing visual impacts to the characteristic landscape.

• Under Alternative D, impacts would be experienced over a longer total time period than other action alternatives because Phase I construction-related impacts would extend over four years instead of two.

Socioeconomics and Environmental Justice

• Under Alternative A, existing recreational opportunities, including recreational fishing in Icicle Creek and related values and spending, could be affected by decreased fish production due to the continued degradation of the existing intake facilities.

• Under all alternatives, including Alternative A, there would not be disproportionate environmental effects on low-income, minority or tribal populations.

• Under all action alternatives, temporary recreational access constraints and delays would reduce recreational visits and related values and spending. Similarly, there would be temporary economic impacts in terms of value of lost time for motorists due to delays during construction.

• Under Alternative C, impacts on socioeconomics would be lowest of the action alternatives because economic impacts from traffic disturbances would be lowest.

• Under Alternative D, impacts on socioeconomics would be the same as other action alternatives, but the impacts would be experienced over a longer total time period, as Phase I construction-related impacts would extend over four years instead of two.

Hazardous Materials and Public Health and Safety

• Under Alternative A, the lead-based materials on Hatchery infrastructure would remain, resulting in continued exposure to LNFH workers and aquatic species. Unsafe work conditions for Hatchery workers, particularly during frazil ice events, would also continue.

• Under all action alternatives, lead-based materials on Hatchery infrastructure would be safely removed and disposed of. Long-term work conditions would be improved, which would decrease risk of worker injury.

• Under Alternatives B and C, construction activities occurring from 10:00 p.m. to 7:00 a.m. could temporarily increase the risk of vehicle accidents, and the associated construction noise and light from during this time period may temporarily affect nearby residents and guests.

• Under Alternative D, the two additional Phase I construction seasons would continue the risk of impacts to public health and safety for an additional two years. Because Phase I construction work would not take place past 10:00 p.m. under Alternative D, the risk of vehicular accidents and noise impacts to sensitive receptors near the intake structure from 10:00 p.m. to 7:00 a.m. would be reduced compared to Alternatives B and C.

• Under Alternative D, noise levels would exceed the nighttime Class A EDNA of 45 dBA or less for several residences off East Leavenworth Road and Cemetery Road near the spillway pool resulting from pumping for the Phase I temporary Hatchery water supply for an 8-month period.

Tribal Interests

• Under Alternative A, there would be no changes in access to or activities at the Wenatshapam fishery. Ongoing impacts on fish passage from existing LNFH operations would continue; fish production at the Hatchery could be jeopardized in the future due to continued degradation of existing facilities.

• Under all alternatives, including Alternative A, there would be no impacts on Indian sacred sites, Indian Trust Assets (ITAs), or traditionally and culturally important hunting or plant gathering areas.

• Under all action alternatives, improved fish passage, reduced potential for fish entrainment, and increased Hatchery production reliability would benefit the Wenatshapam fishery.

• Under Alternatives B and C, Tribal fishery activities could be temporarily impacted during construction from noise disturbance and reduced fishing area from pump screen boxes in the spillway pool. Temporary Hatchery water supply pumping activities at the spillway pool may occur during the same time as scaffolding repair, ceremonial, and fishing activities, but would not impact the ability of the Tribes to perform these functions.

• Under Alternative D, temporary impacts on the Tribal fishery would be experienced over a longer total time period than for Alternatives B and C, as Phase I construction-related impacts would extend over four years instead of two. Pumping from the spillway pool would occur over a period of 8 months during Phase I of construction and could result in possible fish displacement and temporary noise impacts to Tribal fishers.