Biological resources

Federal: Federal Endangered Species Act (FESA) legally protecting special-status plant species. NEPA (national environmental policy act), CWA (clean water act), BLM (Bureau of land management) Sensitive species, U.S. Forest Service (USFS) are all involved in protection of vegetation resources.

State: California Endangered Species Act (CESA), CEQA (California environmental quality act), California Native Plant Protection Act (NPPA), Special-Status Natural Communities, California Native Plant Society,

Local: Mono County and Town of Mammoth Lakes General Plan both contains goals related to vegetation resources.

39.56 acres (0.16 km²) of big sagebrush scrub and 36.86 acres (0.15 km²) of Jeffrey pine will be affected. There is a potential risk that pine fritillary, a non-listed special status tree, will be permanently impacted.

Direct impacts include loss and fragmentation of habitat and the introduction of weeds and non-native species. Temporary indirect impacts are the production of dust and soil disturbance, which can affect plant metabolic processes. Effects in downstream water caused by sedimentation are also possible.

Alternative 3 has the least impact on disturbed vegetation area due to shorter pipeline length, but it was not chosen as the preferred option possibly because of trade-offs in other valued ecosystem components.

Mitigation

Due to the low impact on pine fritillary and to the commonness of big sagebrush scrub and Jeffrey pine, no species-specific mitigation is planned.

To control weeds dispersal, equipment at the site will respect strict cleaning procedures and weed-free certified materials will be used. Non-native species will be removed at decommissioning.

Mitigation success criteria

1. After a three year follow-up period, non-native weeds shall not increase by more than 5% compared to the baseline at decommissioning, excluding cheatgrass.

2. The project shall introduce no new non-native species.

Residual impacts

None mentioned.

The mitigation success criteria seem negligent, as it ignores the most invasive species, cheatgrass. Mitigation focuses on avoiding the introduction of new non-native species, but this technique could become necessary to increase competition on cheatgrass if it ever establishes.

No reason is given to justify why the risk of pine fritillary being affected is low.

Federal: FESA, Migratory Bird Treaty Act, The Bald and Golden Eagle Protection Act, BLM Sensitive Species, USFS.

State: CESA, CEQA, California Fish and Game Code.

Local: Mono County and Town of Mammoth Lakes General Plan.

Direct impacts are noise, night lighting, fugitive dust, entrapment in site basins, habitat loss, and migration obstruction.

Habitat loss will impact the northern goshawk, the pallid bat, the Townsend’s big-eared bat and the Sierra martens.

Rodents will be attracted to well site basins as they become a suitable habitat when filled with water. This source of food will attract birds of prey and trap them in the basins.

Thermal discharge is predicted to have no impact on water temperature due to conductive buffering. Thus, no impact is predicted for the Owens tui chub fish.

The proposed alternative has the least impedance to movement.

Cumulative effects

None mentioned.

Mitigation

As the bat species’ habitat spans a large range, no mitigation is needed.

Survey of bird nests will be done prior to construction, and protection buffers will be implemented if nests are discovered. Effort will be made to schedule construction activities outside of breeding season.

Site basins will be designed to allow trapped wildlife to escape, and no water will be allowed to accumulate.

Crossings will be built to accommodate mule deer migration across pipeline corridors (see figure below). Annual surveys will be done to observe signs of obstruction.

To compensate for the habitat loss of the Sierra marten, wood debris will be left on the ground in disturbed areas to replicate their natural habitat.

Conductive buffering is effective until a tipping point is reached. The EIA mentioned that temperature change due to the project cannot be measured properly because of the confounding effect of climate change. This is an unreasonable excuse because it is possible to use a control river to calculate baseline warming. Moreover, it is surprising that no cumulative effect is mentioned even if the EIA reported the existence of another thermal plant in the vicinity of the current project.

Federal: CWA for regulated wetlands and other water of the U.S., NEPA.

State: Porter-Cologne Act, Lake and Streambed Alteration Program.

An assessment made by a third party determined that the unnamed stream flowing through the project area was not likely jurisdictional under the CWA.

The assessment was not reviewed by USACE (United States Army Corps of Engineers) and should be considered preliminary. There was no further information as to whether it has been done at the end.