The Idaho Sporting Congress (“ISC”) and American Wildlands challenge a decision by the United States Forest Service (“Forest Service”) to sell timber in the Miners Creek and West. Camas Creek watersheds without producing an Environmental Impact Statement (“EIS”) and without addressing the requirements of the Idaho water quality anti-degradation statute. Relying on 1985 and 1990 water quality reports, the Forest Service prepared an Environmental Assessment (“EA”) in lieu of an EIS. ISC contends that the Forest Service’s actions violate the National Environmental Policy Act (“NEPA”), the National Forest Management Act (“NFMA”), and the Clean Water Act (“CWA”). The district court denied ISC’s motion for summary judgment and granted the Forest Service’s cross-motion for summary judgment. This court has jurisdiction pursuant to 28 Ü.S.C. § 1291. We reverse and instruct the Forest Service to prepare an EIS.
FACTUAL BACKGROUND
This litigation concerns the proposed sale of timber by the Forest Service from the Miners Creek and West Camas Creek drain-ages in the, Targhee National Forest in southeastern Idaho. The proposed Miners Creek timber sale consists of 3.1 million board feet of timber from 970 acres in the Miners Creek and West Camas Creek sub-watersheds. The two streams within the proposed sale area, Miners Creek and West Camas Creek, are inhabited by brook trout, a management indicator species for the Tar-ghee National Forest.
In evaluating the environmental effects of the proposed timber sale, the Forest Service did not prepare an Environmental Impact Statement .(“EIS”) preparing instead a less
In July of 1996, the Forest Service proposed the Camas Creek timber sale of 7.2 million board feet within the Camas Creek watershed. The Forest Service again chose not to prepare an EIS for this sale: As the Camas Creek sale also involves logging timber within the West Camas Creek subwat-ershed, it potentiaUy impacts the Miners Creek sale. Though the EA for the West Camas Creek Timber sale states that it takes into account all past, present, and future projects within the watershed, the Forest Service chose not to supplement the Miners Creek EA to reflect the cumulative impacts of the West Camas Creek logging.
STANDARD OP REVIEW
We review de novo the grant and denial of summary judgment. Oregon Natural Resources Council v. Lowe,
In determining whether the Forest Service’s decision was arbitrary and capricious, we “consider whether the decision was based on a consideration of the relevant factors and whether there has been a clear error of judgment.” Marsh,
ANALYSIS
I. EIS REQUIREMENT UNDER NEPA
ISC claims that the Forest Service must complete an EIS because, there are substantial questions about whether the Miners Creek timber sale wül affect water quality and fisheries, and thereby the human environment. NEPA imposes a procedural requirement that an agency must contemplate the environmental impacts of its actions. Inland Empire Pub. Lands v. United States Forest Serv.,
A. WATER QUALITY .
ISC claims that an EIS is necessary because there are substantial questions as to whether the timber sales will have a significant effect on the water quality of Miners Creek and West Camas Creek. Specifically, ISC argues that the 1990 report failed to conduct standard factual and scientific site specific analysis, and failed to provide the analytical data necessary for any public challenge to the proposed sale. Rather, the 1990 report consists of the expert opinion of Forest Service hydrologist Mark Moultin based on the natural topography of sale area.
Seeking to cure this defect, the district court noted that Moultin, who prepared the 1990 report, had earlier conducted the requisite monitoring and sampling in conjunction with a 1985 logging of the West Camas Creek watershed, and found that Moultin’s expertise combined with his 1985 research adequately supported the 1990 study. Similarly, the Forest Service relies on the 1985 report to show that its past management practices have not degraded water quality. Agreeing with the Forest Service and finding that the 1985 report provided sufficient technical support to the 1990 report, the district court concluded that the 1990 report was a “hard look” at water quality issues. We disagree.
First, we find that the 1990 report alone does not satisfy NEPA’s reporting and notice requirements because it fails to provide the public with a basis for evaluating the impact of the proposed sale. Since the 1990 report relies solely on Forest Service hydrologist Mark Moultin’s expert opinion, a successful challenge to the report would entail challenging Moultin’s expertise and opinions, yet, this is the type of challenge we have found impermissible under arbitrary and capricious review. Greenpeace Action v. Franklin,
We further disagree with the district court’s conclusion that the analytical defects in the 1990 report can be repaired by referencing the data from the 1985 report.- The .1985 report fails to adequately support or supplement the 1990 report for two reasons: (1) the scope of the 1985 report differs from that of the 1990 report; (2) there are factual differences between the logging done in 1985 and the proposed logging under the Miners Creek timber sale such as the riparian buffers.
First, the 1985 report’s section on water quality was limited in scope to the Camas Creek watershed and did not cover Miners Creek. The report even cautioned that
[sjince physical characteristics of the inventory area vary so widely, the results from the West Camas Creek drainage cannot be considered to represent the whole area or used in management decisions in areas other than on the drainage from which the measurements were taken.
In addition, the report did not state at what stage of the logging process the monitoring and analysis was conducted and so it remains unclear as to whether the report captured the full effect of logging on water quality.
Substantial questions remain as to the effect that the Miners Creek timber sale will havé on the human environment. The 1990 report indicates that Miners Creek currently has an excess of sediment and that “Additional sediment would further degrade the system.” In light of the failure to provide adequate data to the public, we conclude that an EIS is necessary to explore the substantial questions in respect to whether and what significant effects the sale may have. Mitigation.
The Forest Service also argues that water quality will not be affected by the proposed logging because of the mitigation measures described in the EA that will be undertaken. However, since the effects of the sale will not be known until the EIS is prepared we cannot know whether the mitigation measures are sufficient. In the context of an EIS, an agency is required to “discuss the extent to which adverse effects can be avoided” by mitigation measures. Robertson,
B. FISHERIES
ISC claims that the Forest Service failed to analyze the potential effects of the timber sale on fisheries, and that thé Forest Service failed to adequately notify the public what trout inhabited the sale area streams. These claims implicate both of NEPA’s disclosure goals, i.e., to insure the agency has fully contemplated the environmental effects of its action and to insure the public has sufficient information to challenge the agency. See, e.g., Inland Empire,
Trout are designated as a management indicator species for the 'Targhee National Forest. The Forest Service designates management indicator species “because their population changes are believed to indicate the effects of management activities.” 36 C.F.R. § 219.19(a)(1). Once an indicator species is selected, the Forest Service is obligated to evaluate and state planning alternatives “in terms of both amount and quality of habitat and of animal population trends of the management indicator species.” 36 C.F.R. § 219.19(a)(2); Inland Empire,
Public notification of trout.
Under NEPA the Forest Service has an obligation to notify the public that trout populations are present in Miners Creek and West Camas Creek. Agency regulations require that public information be of “high quality” because “Accurate scientific analysis, expert agency comments, and public scrutiny are essential to implementing NEPA.” 40 C.F.R. § 1500.1(b) (emphasis added).
Agency contemplation of environmental effects on trout.
ISC also argues that the second goal of NEPA, agency contemplation, was not accomplished. Given the existence of brook trout and the potential effects of sediment on Miners Creek arid West Camas Creek, ISC contends that the Forest Service was arbitrary and capricious in not producing an EIS. The EIS that we conclude the Forest Service must prepare should address these potential effects.
C. CUMULATIVE IMPACTS
After the Forest Service approved the Miners Creek timber sale, it proposed another timber sale near West Camas Creek. Since both sales affect the West Camas Creek watershed, ISC contends that the Forest Service is obligated to supplement its EA with an EIS to account for the cumulative impacts of the two sales.
In Save the Yaak Comm. v. Block, we concluded that when agency projects have the potential for cumulative harm an “assessment of connected actions is necessary even if the impact of the proposed action is not significarit.”
While the Miners Creek EA did not address the cumulative impacts of the West Camas Creek timber sale, the Forest Service claims that it did a cumulative iinpacts analysis in the West Camas Creek EA that accounted for the Miners Creek sale. Since the West Camas Creek EA indicates no significant impacts in conjunction with the Miners Creek timber sale, no supplemental EA or EIS is needed. We would find no difference in the result if the Forest Service studies the impact of the West Camas Creek sale on Miners Creek or the impact of the Miners Creek sale on West Camas Creek. It need be done in only one of the studies. The Forest Service expressly states that the “Miners Creek [timber sale] was evaluated in the cumulative effects analysis in the Camas Creek EA.” Since the effects of the two sales were accounted for in the West Camas Creek cumulative impacts analysis, we do not require duplication in the Miners Creek EA. However, that does not answer the question of whether the study was adequate. We note that evidence of the Forest Service’s cumulative impact study is sparse. However, since we require an EIS, any inadequacy in the analysis of ■ cumulative impacts can be addressed there.
ISC contends that Idaho’s anti-degradation policy requires the Forest Service to maintain existing water quality levels unless a formal determination is made that lowering water quality is necessary for social or economic reasons/
Idaho’s antidegradation policy provides that:
The existing instream beneficial uses of each water body and the level of water quality necessary to protect those uses shall be maintained and protected. Where the quality of waters exceeds levels necessary to support propagation of fish, shellfish and wildlife and recreation in and on the water, that quality shall be maintained unless the department finds ..., that lowering water quality is necessary to accommodate important economic or social development in the area in which the waters are located.
Idaho Code § 39-3603 (emphasis added). While the Code uses mandatory language, the preamble to the Code is explicit that the Idaho legislature intended to meet only the federal minimum requirements.
It is the intent of the legislature that the state of Idaho fully meet the goals and requirements of the federal clean water act and that the rules promulgated under this act not impose requirements beyond those of the federal clean water act.
Idaho Code § 39-3601. The federal antide-gradation policy requires only that “[e]xisting instream water uses and the level of water quality necessary to protect the existing uses shall be maintained and protected.” 40 C.F.R. § 131.12. Since no Idaho court has addressed this conflict, we must determine whether .the expressed legislative intent in the preamble or the plain language of the statute will control.
Under the plain language of the statute, ISC contends that the Forest Service would have to show that there are no effects on water quality, i.e., no sediment, even if it did not change the water quality for beneficial uses. Under ISC’s reading of the statute, the Idaho antidegradation policy presents an absolute bar to any adverse effects bn water quality. We are persuaded however "by the legislative intent that only obligates the Forest Service to maintain the federal standard as set forth in 33 U.S.C. § 1313 and 40 C.F.R. § 131.12. We recognize that “water quality” represents a quality range and not a single point. However, until further studies are completed on the two streams, we lack sufficient facts to determine whether Idaho’s antidegradation statute has been violated.
III. NFMA CLAIMS
ISC makes two main arguments under the NFMA: that the Forest Service failed to monitor population trends of trout and to determine the relationship of population to habitat changes as required by 36 C.F.R. § 219.19, and that the Forest Service failed to monitor trout as required by Tar-ghee National Forest Land Management Plan (“Targhee LMP”).
The NFMA imposes substantive duties on the Forest Service that include providing for “diversity of plant and animal communities.” Inland Empire,
Next, ISC argues that the Tar-ghee LMP also requires the Forest Service to “monitor trout populations on streams which will be affected by Forest activities.” Under 16 U.S.C. § 1604(i), Forest Service site specific plans must be consistent with the forest-wide Land Management Plan (“LMP”). Id. at 757. However, as with federal regulations in Inland Empire, we defer to the Forest Service’s expertise in interpreting its LMP.
CONCLUSION
We hold that the Forest Service has failed to meet its NEPA requirements for public disclosure of information and has failed to take a “hard look” at the effects of the proposed timber sales. The Forest Service must complete an EIS. Other issues cannot be decided without the EIS. We hold that the standard for judging the quality of the water under Idaho law is the federal standard. The judgment of the district court is REVERSED and the Forest Service is directed to prepare an EIS before deciding whether to proceed with the Miners Creek timber sale.
REVERSED.
Notes
. It is unclear whether the proposed timber sale actually does involve logging within 100 feet of a riparian area but the mitigation measures allow logging up to a 25 foot buffer.
. We also note that in its summary judgment memorandum before the district court, the Forest Service argued that this quote did not indicate that trout were present in Miners Creek. There the Forest Service claimed that "it is difficult to imagine ... exactly how any of the planned logging activities might affect the 'access and dispersal’ of a group of non-existent fisherman, looking for non-existent trout in the intermittently flowing tributaries that 'feed' Miners Creek.”
. The Forest Service argues that ISC failed to preserve this claim for appeal. We disagree. First, ISC did not limit its complaint to Camas Creek and Beaver Creek. Second, ISC’s brief to the district court makes a three page argument addressing the Idaho water quality issues with respect to Miners Creek and West Camas Creek, the two creeks within the forest boundaries.
