The surface of the pad, outside the sump enclosure, supports very little vegetation. There are no existing trees or shrubs, and only a very sparse herbaceous component (<2% cover) is present. These scattered forbs and graminoids are most conspicuous on the bordering cut banks, where individuals and/or group of two special status plants are resident. Hall’s sedge has colonized all three of the cut banks. A total of approximately 15 square feet of area is occupied by this species on the east cutback, with a lesser amount located above the bank at the fringe of the bordering lodgepole pine stand. On the north side, individuals and a single clump of Hall’s sedge occupy a total of several square feet on the bank, and 20-plus square feet above it. Only three (3) isolated plants of this species are resident on the south cutback (at the extreme west end), though additional individuals were scattered within the open lodgepole stand above. A single plant of ash penstemon is resident on the east cut-bank. All these special status plants are located on or above the bordering cut banks, off the floor of the pad, and outside any activity zones. The vegetation within the sump enclosure contrasts in-part with that without. Completely surrounding the pond, beginning at the water’s edge, is a dense 3- to 4-foot band of herbaceous vegetation which includes a fairly diverse assemblage of water-dependent species (Carex, Scirpus, Eleocharis, Typha, Potamogeton). Outside this green donut, but within the sump enclosure on somewhat drier disturbed soil, is a scattering of herbs including Poa secunda. Resident in this latter area are several small groups of ash penstemon and a single clump of Hall’ sedge. No noxious weeds have been introduced onto this developed well pad or the surrounding environment. Existing Well Pad 31-17: This site is located on a leveled area bounded on three sides by relatively flat terrain with open stands of red fir-lodgepole pine forest, and on the west by a hill occupied by a moderately dense stand of large mature red fir. Development at this site consists of an enclosed well and large sump. The area outside the sump has a gravelly-cobble surface and supports only a scattering of graminoids and forbs. Within the enclosure, a green halo of dense herbaceous growth, 3-6 feet wide, almost completely encircles the water in the sump. Outside this initial border, on drier soils, is an open band that includes a variety of forbs as well as lodgepole seedlings. No special status plants are resident on this site. No noxious weeds have been introduced to the site. Previously Approved Exploration Well Pad 13-18: This site straddles the southern end of a clear-cut in which approximately one half of the site is to be located. The remaining half is located in a lodgepole pine stand adjacent to the clear-cut on the northeast side. This relatively dense stand of lodgepole pine is characterized by narrow crowned pole and mature size trees, the former dominating. Average dbh is approximately 8 inches (4-14 inches) and the crown cover is approximately 70 percent. The height of stand dominants is 70-80 feet. Young regeneration is sparse as is the understory in general. There is a light-to-moderate cover of coarse woody debris. The clear-cut area has no overstory trees but is well stocked with lodgepole seedlings. It has a 10 percent herbaceous cover. There is a relatively dense concentration of coarse woody debris on the highly disturbed surface. No special status plants occur on the site. Previously Approved Exploration Well Pad 56-18: This site is occupied by a selectively cut over red fir stand. This open residual stand has an overall canopy cover of less than 40 percent and contains a variety of size classes with saplings being most prevalent. The average diameter of residual red fir is approximately 10 inches excluding the included small thickets of saplings and young poles. Mature dominants were approximately 120 feet high. There is both a shrub and herbaceous component in the understory which together averages approximately 25 percent cover. No special status plant species occur on the site. A group of three (3) sugar stick occur very close to the southern boundary of the site. Proposed Well Pad 26-7: This site supports a dense stand of lodgepole pine forest with a canopy closure varying from 70 percent in the southern half to 90 percent in the northern half. It is made up primarily of dense younger size classes. There are less than 10 percent mature trees scattered through the area. These have an average diameter of approximately 15 inches. A line of medium-sized red firs occur adjacent to the road along the southern boundary of the site. The herbaceous layer throughout this site is sparse. No special status plant species occur on this site. Proposed Well Pad 84-7: This site is located within the red fir-lodgepole pine forest and is occupied by a sparse cut-over stand. The residual overstory trees have a mean dbh between 20-24 inches. Overstory canopy cover is less than 25 percent. An understory of saplings and a few pole-sized trees provide an additional 10-15 percent cover. Ground cover is sparse and the soil surface is very disturbed. No special status plants occur on the site or in the surrounding area. Proposed Well Pad 64-8: This site is located on a ledge at the base of a large mountain hemlock-red fir forest. The site is occupied by a cut over stand of red fir-lodgepole pine. The stand includes several Western white pine and mountain hemlock. Canopy cover is approximately 25 percent. Residual trees are pole and small mature size. Several small concentrations of saplings make-up a sparse understory. Pumice is exposed on the soil surface. No special status plants occur on the site or in the surrounding area. Proposed Well Pad 73-13: This site lies on the southern boundary of a large clear-cut, the fringe of which is included in the proposed well pad. The timbered portion of this site is presently occupied by a multi-aged red fir-lodgepole pine stand. The overstory canopy of this forested area is approximately 40 percent, divided fairly evenly between lodgepole pine and red fir. Mature red fir dominants, ranging from 12-24 inches dbh, provide 5-10 percent of this canopy cover, the balance being provided primarily by pole-size trees. The understory herbaceous layer is sparse. A very large population of the special status species, Hall’s sedge is widely distributed in the adjacent clear-cut; however, no plants were observed on site. Proposed Well Pad 15-16: This site is occupied by a selectively cut over stand of red fir-lodgepole pine. The residual overstory is composed of small mature trees (11-24 inches dbh) and poles; predominantly red fir but also including Western white pine and lodgepole pine. The overstory cover varies from 40-50 percent. The understory includes dense groups of lodgepole saplings, most concentrated on the northern quarter of the site. There is also a 5-10 percent shrub cover in openings. No special status plants occur on this site.

Proposed Well Pad 26-17: This site has been partially cut over and is presently occupied by a residual stand of red fir which is irregularly arranged as a result of logging but averages approximately 50 percent canopy cover. The multi-aged red fir occur in dense groupings interspersed with openings. Larger, mature trees occur on the western half of the site. The approximate average dbh of the larger residual groups is 13 inches. Stand dominants are 80-100 feet high. The ground cover in openings averages 25-30 percent (exceeding 50 percent in local areas). A number of colonies of sugar stick occur in close proximity to the north and east boundaries. Almost all these plants occur under complete canopies provided by small groups of residual red fir. For the Proposed Action and Alternative Site A only, the proposed location of this pad has been reduced in size and shifted southwest to avoid these populations and retain the integrity of the existing microhabitat of this sugar stick population. Proposed Well Pad 72-17: This site is a very open cut over red fir-lodgepole pine stand of less than 40 percent canopy cover. The understory vegetation is quite sparse. There is a light to moderate distribution of coarse woody debris on this surface. No special status plant species occur on the site; however, a colony of sugar stick is located fairly close to the northeast corner of this proposed pad. Proposed Well Pad 16-18: This site is occupied by a partially harvested, irregular stand of lodgepole pine. Large openings are interspersed with dense groups of pole-sized trees. The mean dbh of overstory trees is 8-9 inches. The average canopy cover is approximately 50 percent. Groundcover is composed of groups of saplings and herbaceous species and is moderate in density. The forested portions of the site have a moderate cover of coarse woody debris. No special status plants occur on the site. However, a population of Hall’s sedge occurs in openings immediately east of the site near Forest Service Road 45N27. Proposed Well Pad 25-18: This site is located within the lodgepole pine forest community. It supports a lodgepole pine stand well represented by age-size classes from small poles through mature trees, the average dbh being approximately 9 inches. The average canopy cover over much of the site is approximately 70 percent but the stand opens up along the road which bisects the site. The vegetative ground cover is sparse. There is a good duff layer and a light to moderate distribution of course woody surface debris. No special status plant species were noted on this site, though a sizeable colony of Hall’s sedge is distributed quite liberally over more open disturbed habitat just several hundred feet south of the proposed pad. Proposed Well Pads 51-18: This site is located within the red fir-lodgepole pine forest community. The dominant species is red fir. The stand is open as a result of selective logging. Canopy cover is approximately 25 percent. The stand is composed of pole-sized and small mature trees. The understory is sparse. In the northeast corner of the site there are several large (greater than 24 inches dbh and greater than 100 feet tall) red fir trees. No special status plants occur on this site or in the immediate surrounding area. Proposed Well Pad 62-18: This site is occupied by a selectively cut over red fir-lodgepole pine stand of less than 40 percent canopy cover. Mature red fir residuals are unevenly distributed throughout the stand but provide less than 10 percent canopy cover. These residuals average approximately 20 inches dbh and stand dominants approach 120 feet in height. The balance of the cover is provided by poles and saplings, about evenly divided between red fir and lodgepole pine. The herbaceous ground cover is less than 2 percent on undisturbed portions of the understory, but 5-10 percent in disturbed openings. No special status species occur on the site. Proposed Well Pad 77-18: This site is occupied by a moderately dense stand of red fir. The average canopy cover is 60 percent. There are openings that are a result of selective logging. The stand has a heterogeneous structure - approximately 25 percent of the canopy cover is made up of medium-sized trees (greater than 24 inches dbh), and 75 percent by smaller trees in intermediate and understory layers. Ground cover is sparse. Proposed Well Pad 83-18: This site is occupied by a selectively cut over red fir-lodgepole pine stand with an average canopy cover of approximately 40 percent. This stand is multi-aged, but small (11-24") mature residuals are most prevalent. This mature component is weighted heavily to red fir but a good portion of Lodgepole pine are included. The red fir residuals average approximately 18 inches dbh and the lodgepole pine about 13 inches dbh. Red fir stand dominants are approximately 100 feet high. The ground cover is sparse. No special status species occur on the site.

Pipeline Corridors The composition and structure of the vegetation communities that would be traversed by pipeline corridors within the Project wellfield area are summarized in Table 3.3.4. Four populations of special status plant species occur in the vicinity of the pipeline corridors (see Figure 3.3.6). Individual populations of sugar stick occur close to an injection pipeline corridor and within a production pipeline corridor. Individual populations of Hall’s sedge occur within the immediate vicinity of the fresh water line corridor and the corridor near proposed well pad 16-18. The entire length of the fresh water pipeline would be buried in existing roads or in maintenance roads within geothermal piping corridors. Transmission Line Corridors Table 3.3.5 summarizes the vegetation communities traversed by proposed transmission line corridors (D1 and D2) within the wellfield area from the Project Alternative power plant sites to their interconnection with the proposed Fourmile Hill Project alternative transmission line utility corridors. See Exhibit 4 (pages 4-98 and 4-99) for a summary of the vegetation communities associated with the alternative transmission line utility corridors described in the Fourmile Hill Project EIS/EIR. The following discussion includes a description of the environment affected by each corridor segment. Tie-In Line D1 (Proposed Action): Approximately one (1) mile of the 1000-foot wide siting corridor would traverse undulating, broken, and moderately sloping terrain occupied by partially cut over stands of red fir-lodgepole pine forest with an average canopy cover of less than 40 percent. Mature residual trees (>11 inches dbh) provide one-quarter to one-half of the total canopy cover. Minor stands with a canopy cover of approximately 50 percent are included. Understory regeneration is predominately lodgepole pine. The groundcover is sparse. Stands of uncut mid- to late-seral red fir occur on both sides of the alignment where it crosses a spur ridge in the center of Section 7, immediately east of a small hill at the northwest end of the ridge. These stands have approximately 70 percent canopy cover. Mean dbh is estimated to be 11-24 inches, but there is a good stocking of medium trees (24-36“ dbh) in the stand on the east side. There is a gap of approximately 500 feet between these two stands. This corridor has been partially logged and has characteristics similar to those described above for undulating, broken, and moderately sloping terrain. The most northerly -mile of the siting corridor would traverse flat terrain occupied by relatively uncut stands of lodgepole pine forest. The overstory canopy cover averages approximately 70 percent and is made up of pole and small mature trees with a mean dbh of <11 inches. Understory regeneration stocking is moderate, and herbaceous groundcover is sparse. No special status plant species occur within 500 feet of the center of the alignment. The Riparian Reserves protecting ephemeral ponds, in Alcohol Crater and an adjacent basin to the north, are also completely outside this 1,000-foot corridor. Tie-In Line D1 (Alternative Site A): The center of the alignment in the southern 0.9 miles of the siting corridor would traverse cut-over red fir-lodgepole pine forest similar to that described for the Proposed Action. However, within 500 feet of the center, on the east side of the alignment, are the following sensitive resources: (a) the outer boundary of a Riparian Reserve; (b) populations of two special status plants, Kruckeberg’s fern and Northern daisy; (c) approximately 4.5 acres of late-successional red fir; and (d) a stand of mature mountain hemlock-red fir approximately four (4) acres in size. The western one-half of the alignment bypasses these sensitive resources. The center of the alignment in the 0.3 mile intermediate section of the corridor would traverse a stand of mature red fir. The mean dbh of the stand is between 11-24 inches and canopy cover is between 40-59 percent. The western 250 feet of this section of the corridor would bypass the mature red fir stand and is characterized by open stands of red fir-lodgepole pine. A riparian reserve is located within 500 feet of the center of the alignment on the east side. The northern ½-mile section of the corridor would traverse moderately dense lodgepole pine forest as described for Tie-in segment D1 (Proposed Action).

Table 3.3.4: Vegetation Communities Traversed by Pipeline Corridors within the Project Wellfield Area

Corridor	Communitya	Structureb,c	Proposed Action (acres)	Alternative Site A (acres)	Alternative Site B (acres)
Production Pipe	DIST	0	2.4	2.4	2.4
	LP	2S	2.0	2.0	2.0
		3M	0.8	0.8	1.4
		3D	2.2	2.2	2.2
	RF-LP	4M	3.8	3.8	3.8
		4P	9.2	14.0	16.2
		4S	5.7	5.7	3.3
	RF	4S	0.0	0.0	1.2
		4M	0.0	0.0	0.8
Injection Pipe	DIST	0	3.0	3.0	3.0
	RF-LP	3P	0.9	0.9	0.9
		4P	14.3	14.3	14.3
		3S/2P	2.4	2.4	2.4
		4S	3.3	3.3	4.5
		4M	1.1	1.1	1.1
Production and Injection Pipe	DIST	0	0.4	0.4	0.4
	RF-LP	3P	4.1	4.1	4.1
		4P	7.3	4.1	0.0
		4M	4.1	1.2	0.0
		4D	1.2	1.2	1.2
Total Area of Pipeline Corridorsd:			68.2	66.9	65.2
a Community type: RF - red fir forest; LP - lodgepole pine forest; RF-LP - red fir-lodgepole pine forest; DIST - disturbed area b Size class: 1 - seedling; 2 - sapling 1-5" dbh; 3 - pole 6-11" dbh; 4 - small 11-24" dbh; 5 - medium large >24" dbh c Canopy class: S - sparse 10-24%; P - open 25-39%; M - moderate 40-59%; D - dense 60-100% d Sum of production fluid pipeline corridor, injection fluid pipeline corridor, shared production and injection fluid pipeline corridor, and new pipeline corridor maintenance roads. The fresh water pipeline corridor was not included because it is within existing roads or in maintenance roads.

Table 3.3.5: Vegetation Communities Affected by Proposed Transmission Line Corridors within the Project Wellfield Area

Vegetation Communitya	Community Structureb,c	Proposed Action (acres)		Alternative Site A (acres)		Alternative Site B (acres)
		D1	D2	D1	D2	D1	D2
LP	4M	4.0	0.0	4.0	0.0	4.0	0.0
RF-LP	4S	0.0	9.0	0.0	9.0	0.0	7.3
	4P	9.7	7.6	12.1	2.5	15.9	0.0
	4M	1.8	0.0	2.9	0.0	2.9	0.0
RF	4D	0.0	0.7	0.0	0.0	0.0	0.0
Totals:		15.5	17.3	19.0	11.5	22.8	7.3
a Community type: LP - lodgepole pine forest; RF-LP - red fir-lodgepole pine forest; RF - red fir forest b Size class: 4 - small 11-24" dbh c Canopy class: S - sparse 10-24%; P - open 25-39%; M - moderate 40-59%; D - dense 60-100%

Tie-In Line D1(Alternative Site B): The corridor would traverse small, open to moderately dense red fir-lodgepole pine forest for the first ½-mile out from the power plant site. Two (2) individual sugar stick plants are located on the southern boundary of the corridor, and 17 plants of sugar stick are included in the northern half of the corridor. The communities traversed by the remaining legs of the corridor are identical to those described under Tie-In Line D1 (Alternative Site A). Tie-In Line D2 (Proposed Action): Approximately 0.3 mile of the alignment would traverse slightly undulating terrain occupied by selectively harvested stands of red-fir lodgepole pine forest with <40 percent canopy cover and a sparse understory. The composition and structure of these stands is very similar to that described on proposed well pad 62-18. Approximately 0.3 mile of the alignment would traverse similar terrain also occupied by selectively harvested stands of red-fir lodgepole pine forest, but logging has not been as intensive. Canopy cover for the most part averages approximately 40 percent, with minor included stands of 50 percent. The composition and structure of the stands are similar to those described on proposed well pad 83-18. The understory is denser, including more saplings and occasional dense groups of pinemat manzanita. Approximately 0.1 mile of corridor would traverse a mid- to late-seral red fir forest located on the hill immediately west of existing well pad 31-17 (NW¼ of Section 17). The canopy cover of this forest is approximately 70 percent. The center and northern half of the corridor includes a late-successional forest stand. The southern half of the corridor is comprised of a younger red fir stand. Approximately 0.75 mile of the alignment on the east end traverses an irregular hummock side slope that is highly disturbed from rather intensive logging. The residual red-fir lodgepole stands, made up of small and pole-size trees, provide only a 10-25 percent canopy cover. The understory is quite open consisting of a ground cover of lodgepole seedlings and a sparse covering of pioneer herbaceous species. Several colonies of the special status species, sugar stick, occur within the 1000-foot corridor. A total of 17 individuals occur in several groups on a low hill immediately south of Alcohol Crater (NE¼ of the NE¼ of Section 18). A single individual sugar stick occurs within the red fir stand identified above. A third colony of 16 sugar stick occur in the immediate vicinity of the eastern terminus of Tie-In Line D2. All of the populations are very close to the center of the proposed alignment, but the southern one-third of the corridor bypasses them.

Tie-In Line D2 (Alternative Site A): The corridor would traverse partially harvested red fir-lodgepole pine forest for 0.2 miles out from the power plant. A colony of sugar stick is located within this section of corridor approximately 200 feet north of the center of the corridor. Two (2) isolated individuals of sugar stick occur within the corridor approximately 200 feet south of the center of the corridor. The center of the corridor would intersect a dense fragment of red fir forest approximately 0.2 miles east of the power plant and traverse it for approximately 350 feet. The northern portion of the corridor would include a late-successional stand of red fir approximately five (5) acres in size. Occurring within this stand is a single sugar stick plant. The southern portion of the corridor bypasses the red fir stand. The eastern 0.75 miles of the corridor would traverse very open, cut over red fir-lodgepole pine forest. Near the terminus of line D2 (Alternative Site A) is a population of sugar stick. Tie-In Line D2 (Alternative Site B): The corridor would traverse very open, cut over red fir-lodgepole pine forest as described for tie-in line D2 (Proposed Action). A population of sugar stick occurs near the terminus of the line. Road Construction Table 3.3.6 summarizes the vegetation communities affected by road construction and improvement within the Project wellfield area. No special status plant species are affected.