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Altamont Scientific Review Committee Agreements & Recommendations

SRC agreements represent consensus recommendations of the SRC developed during its meeting deliberations. Consensus agreements stand unless new information arises. At that time, the SRC member with new information will request that the SRC facilitator place it on the appropriate SRC agenda for discussion and reconsideration.

The SRC submits its recommendations to the County Planning Director.

Additional Studies

(Feb 2007 SRC Meeting Summary P12)

The SRC discussed the approach to the monitoring program and agreed that some of the provisions of the settlement agreement, such as the blade painting study, may require additional studies outside scope and costs of the current monitoring program to avoid confounding monitoring results. If the monitoring program includes too many mortality reduction schemes, it may fail to provide conclusive data on each scheme's effectiveness. However, the SRC remains undecided on this issue, and decided to defer further deliberations on it until the Parties and Companies return with more answers to outstanding questions.

Behavior Use and Relative Abundance

(Feb 2008 SRC Meeting Summary P78)

SRC members agreed that bird use data should be integrated into the mortality analysis to the extent possible so the estimates account for raptor population fluctuations that might influence fatality statistics. To work toward this goal, they agreed that all possible bird abundance and use data for the four focal species should be gathered for evaluation and possible integration. The information will be carefully reviewed and any use of these data will first be discussed. The SRC also reiterated its recommendation for acquiring power generation or turbine operating hours data to similarly account for fluctuations in turbine operation.

Blade Painting--AWI Hodos Study

(Feb 2007 SRC Meeting Notes P12)

The SRC agreed that AWI should move forward with the study and present study plans to the SRC.

Buena Vista Repowering Project

(Dec 2006 Meeting Highlights P3)

SRC open to serving as Contra Costa Technical Advisory Committee.

Burrowing Owl & American Kestrel Study Design

(Dec 2006 Meeting Highlights P3)
200 turbines recommended for study on Burrowing Owl and Kestrel

  • The SRC agreed for the first year to focus the four-month study in two 2-month periods, September-October 2007 (when mortality is most likely to occur) and in the spring, probably March-April (when predators are searching for food for young) to observe if there is a seasonal difference in scavenging rate.
  • The study will sample 200 turbines every other day for two months, or 6000 total turbine searches per season and 12,000 searches for the year.
  • Using a 4 turbine/hour search rate, the study will take 3000 hours total for the four-month period. The trade-off is that the number of hours for this focused study is still less than what would have been spent on a much larger Altamont wide monitoring study (i.e., sampling every two weeks).
  • The MT will provide the SRC with more information about study plot locations.
  • The study should as much as possible overlap with existing monthly search plots.
  • The MT should check with Alameda County if this item should go before the Board of Supervisors on Feb.27 (Feb.13 deadline).

Data Transparency

(Feb 2008 SRC Meeting Summary P78)
The SRC reiterated its previously made recommendation that turbines it ranked 8-10 on a hazard scale of 1-10 be removed as one measure toward achieving the 50% reduction in raptor mortality required by the Settlement Agreement. Since the winter shutdown was shorter than three months, the SRC additional recommendation to remove turbines assigned ratings 7 and 7.5 is in effect. (See P68_Turbine List for SRC Selection of Dangerous Wind Turbines 12/21/07 and P69_SRC Hazardous Rating Scale 2/1/08).

The SRC agreed that the MT should create a shared public database to provide access to the following data:

  • 1998-2003 CEC NREL Fatality Data (Used to Develop the 2004 CEC Report)
  • 2005-2007 MT Fatality Data (Used to Develop the 2008 Monitoring Report)
  • Bird Use Data
  • Turbine Operation Data

Data-Related Confidentiality

(Feb 2007 SRC Meeting Notes P12)
The SRC agreed to a protocol for handling confidential data:

  • It will not be shared outside SRC/MT
  • It will not be e-mailed
  • Companies should label materials "Confidential"

Diablo Winds Monitoring

(Apr 2007 SRC Meeting Summary P28)
SRC members were in consensus that continuing to gather data at Diablo Winds is critical as repowering seems likely to reduce avian mortality significantly and more directly comparable data is needed, and because the settlement parties expected the SRC to incorporate data from the repowering projects into the overall analysis stemming from the monitoring program. To ensure this occurs, the SRC agreed to shift a portion of the monitoring program's proposed 2.5-year budget from "Addressing Additional SRC Requests" to a new line item to continue monitoring at Diablo Winds. These mortality data will allow the monitoring team and the SRC to evaluate repowered versus non-repowered sites. These data will be critical to adaptive management strategies.

Feathering versus Lockdown

(Dec 2007 SRC Meeting Notes P71)
SRC members decided feathering versus lockdown of turbine blades when turbines are not operating is not a potential management strategy. There appears to be no clear pattern in the data and multiple confounding factors. Statistics demonstrate there is a great deal to learn about burrowing owl mortality in the APWRA and underscore the value of conducting a nocturnal behavioral study to understand the factors, including predation, that affect burrowing owl fatalities near turbines.

FPLE Credit for Removing High Risk Turbines - Directly to File

Hazardous Turbines

(Jan. 4, 2008 SRC Meeting Notes P72)
All towers and turbines that were rated 8-10 are recommended for removal (P69). If the winter shutdown is not extended to at least three full search cycles (anticipated to be about 3 months), towers and turbines rated 7 and 7.5 are recommended for removal. The SRC recommends that it will consider evaluating turbines and towers not previously evaluated for hazard and removal.

(Feb 2008 SRC Meeting Summary P78)
The SRC reiterated its previously made recommendation that turbines it ranked 8-10 on a hazard scale of 1-10 be removed as one measure toward achieving the 50% reduction in raptor mortality required by the Settlement Agreement. Since the winter shutdown was shorter than three months, the SRC additional recommendation to remove turbines assigned ratings 7 and 7.5 is in effect. (See P68_Turbine List for SRC Selection of Dangerous Wind Turbines 12/21/07 and P69_SRC Hazardous Rating Scale 2/1/08).

Management Strategies

(Aug 2007 SRC Meeting Notes P53)
The SRC agreed to recommend the following short-term management strategies to meet the Settlement Agreement's requirement for a 50% mortality reduction by November 2009:

  • Classify unclassified turbines
  • Remove/relocate Tiers 1&2 of the newly classified turbines
  • Reiterate previous recommendation that all Tier 1 turbines be removed/relocated
  • The SRC also recommends repowering as a strategy to reduce mortality in the long-term.

Management Strategies – Winter Shutdown

(Sept. 2007 SRC Meeting Notes P49)
The SRC agreed to recommend a one-year four-month winter shutdown for the 2007-08 year, to strive to achieve the goal of a 50% reduction in mortality for the four focal raptor species as a whole, with the following conditions:

  • The SRC consider recommending a separate behavior study of burrowing owls
  • The shutdowns be sequenced with the timing of searches, so turbines are searched shortly after being shut down, to improve the validity of the data.
  • The shutdown period would start in mid-October and end in early March, with each turbine shut down for four months, to allow enough time to synchronize the shutdown with the searches while closely achieving a Nov. 1, 2007 to Feb. 28, 2008 shutdown.
The recommendation was made with the following caveats:
  • It may not have an effect on burrowing owl mortality
  • It may not reach the 50% goal
  • The SRC may make additional recommendations based on the results of the shutdown, including possibly recommending a full shutdown in subsequent years.

The SRC will attempt to estimate the potential effect of the shutdown for the entire year. The decision was based on data and analyses of the previous two years of winter shutdown, including the Monitoring Team's 9/12/07 Winter Shutdown Data Tables (M15), Julie Yee's 9/11/07 Winter Shutdown Data Analysis (M16 and M16b) and Wally Erickson 's Updated Seasonal Shutdown Analyses 9/12/07 (M13).

Monitoring Analysis

(Feb 2008 SRC Meeting Summary P78)
For the monitoring report, the SRC agreed the minimum unit of analysis for comparison will be string per season (adjusted for number of turbines). The SRC and MT will arrive on an agreement for the definition of a season. Both the seasonal and annual rates will be presented.

(Feb 2008 SRC Meeting Summary P78)
Another issue in making data from the multiple studies comparable is the definition of bird sizes. Sue Orloff used a different definition than the other two studies in her research (Orloff and Flannery 1992, 1996). The SRC agreed on using the following bird size definitions for the analyses:

  • Small: Hummingbird to mourning dove
    • (This size includes kestrel & burrowing owl)
  • Medium: Pigeon to raven
  • Large: Red-tailed hawk to golden eagle

(Feb 2008 SRC Meeting Summary P78)
The SRC agreed:

  • The adjustment factor for Golden Eagle will be ˜1, which corresponds to nearly zero scavenger removal.
  • To gather information for potentially refining scavenger removal rates, the Monitoring Team will continue tracking feather spots found in the second month of the American Kestrel Burrowing Owl Study this spring, visiting sites once per week until those feather spots have been followed over one search interval (approximately 37 days). These searches can continue through the end of May.
  • After the study, the MT will analyze whether the study substantiates a need for a change in the scavenger removal rate and return to the SRC with a recommendation.

(Feb 2008 SRC Meeting Summary P78)
The SRC agreed that there will be four analyses in the baseline comparison:

  • One analysis would use all data from 2004 and 2008 extrapolated to the entire APWRA.
  • A second analysis would consider only turbines searched both in the 2004 and 2008 studies, which represent about 20% of Altamont turbines.
  • Each of these analyses would be developed twice, once using 2004 assumptions and once using 2008 assumptions, to ensure matched comparisons since the baseline established by the settling parties is based on the 2004 study. The comparison to 2004 turbines using 2004 assumptions and extrapolated to the entire Altamont is as directed by the County.

Monitoring Period

(Feb 2008 SRC Meeting Summary P78)
SRC members agreed that they have an interest in looking at multiple analyses. They agreed to look at three spans:

Another issue in making data from the multiple studies comparable is the definition of bird sizes. Sue Orloff used a different definition than the other two studies in her research (Orloff and Flannery 1992, 1996). The SRC agreed on using the following bird size definitions for the analyses:

  • 1-year span for each year
  • 2-year span for Year 2 & 3
  • 3-year span

They agreed to consider inter-annual variation and the trend over the three years.

Monitoring Program: Pylons and End-Row Turbines

(Apr 2007 SRC Meeting Summary P28)
The SRC recognized the importance of studying the specific effects of adding pylons and removing risky end-row turbines on raptor behavior and mortality.

Monitoring Program Recommendations - Directly to File

Monitoring Protocols Altamont-Wide

(Dec 2006 Meeting Highlights P3)

  • Will measure 45% reduction in pooled species
  • Will examine individual species % reduction, but at lower level of precision than pooled species (Red-Tailed Hawks fatalities will be difficult to reduce.)
  • Adaptive management in year 4 and beyond
  • Initiate study with enough turbines beyond the 2000 to ensure the sample size will remain 2000 over the course of the study.

Monitoring Protocols

(Feb 2007 SRC Meeting Notes P12)

  • The SRC agrees that the intensive sample design study for burrowing owls and American kestrels is an integral part of the Altamont-wide monitoring program and if not implemented, the search interval for the Altamont-wide program should be reduced to every two weeks instead of every 30 days.
  • All turbines except Northwind, Diablo and Buena Vista will be included in the study. Also excluded are the turbines on East Bay Regional Park District property.
  • The SRC assumes that the sample size of 2500 will accommodate turbine attrition, including any turbines that might be removed over the life of the study.
  • The Monitoring Team should replicate the same criteria used to choose the first 2200 study turbines to choose the final 300.
  • The MT, for its six-month analysis, should consider the association of fatalities with the number of rock piles as well as just rock piles and mortality. This will help to determine if rock pile removal should be evaluated further.
  • The scope of services should include a line item for work and analyses requested by the SRC.

Monitoring Team - Directly to File

Monitoring Two Sets of Conditional Use Permits

(Apr 2007 SRC Meeting Summary P28)
The SRC agreed that a different approach to monitoring for Settling Party turbines and non-Settling Party turbines is not needed. However, it will be difficult to isolate effects on the non-settling party towers compared to the settling parties. Factors contributing to reduced mortality are not easily isolated in data analysis because the non-settlement turbines are small in number and dispersed throughout the APWRA.

Power Output Data

(Dec 2006 Meeting Highlights P3)

Counties change permits to require companies to provide power output data for analysis. Data should be weekly from Oct 2005 to current, from now into the future.

Develop a confidentiality agreement between wind farm companies and analytical team to review and analyze wind power information.

Relocating Turbines

(Jan. 4, 2008 SRC Meeting Notes P72)
The SRC recommended that the companies consult with the SRC or a company point person trained by the SRC on removing and relocating turbines. The SRC could train the point person on relocation guidelines and situations to avoid when removing turbines that could increase the potential hazard for raptors in the Altamont. When getting ready to remove a turbine, the company could consult with the SRC or point person. The company could consult with the trained person about turbine removals that create gaps or relocations.
Citation: Smallwood and Spiegel (June 2005); SRC previous recommendation regarding tiers; and Repowering a Portion of the Altamont Pass Wind Resource Area 1998 Draft Environmental Impact Report.

(Apr 2007 SRC Meeting Summary P28)
The SRC recommended that any relocated turbines be moved to lower risk sites designated Tiers 4, 5 or 6, otherwise companies should consult on new locations with the SRC. The SRC supports flexibility in the companies' approach and the use of professional judgment. When a company decides to move a turbine to a site other than Tier 4, 5 or 6, or one that is not classified, or if the company has special considerations, the company should consult with the SRC.
Citation: Smallwood and Spiegel (June 2005); SRC previous recommendation regarding tiers; and Repowering a Portion of the Altamont Pass Wind Resource Area 1998 Draft Environmental Impact Report.

Rock Piles

(Dec 2006 Meeting Highlights P3)
By Sept 1, 2007, rock piles should be 100 meters from turbines. Wind companies should note exceptions due to slop or other factors and schedule time at the SRC meeting to provide an explanation and photo.

Sample Size

(Feb 2007 SRC Meeting Notes P12)
The SRC agreed that, under the new settlement agreement goal of a 50% reduction in mortality, the sample size will remain at 2500 turbines (under the assumption that the reduction goal is based on pooled, not individual species mortality), as this will still allow for results with a scientifically credible margin of error of ±10%. The SRC agreed, however, that the sample size might have to increase to include monitoring of turbines used in the blade painting experiment and those subject to other mitigation measures.

Species Studied

(Feb 2007 SRC Meeting Notes P12)
The SRC agreed that assuming cost constraints will continue, the targeted reduction in mortality will be applied to the pooled mortality of four target species: golden eagle, red-tailed hawk, burrowing owl and American kestrel. However, at least one SRC member expressed reservations about the pooling of these species.

Because red-tailed hawks have not responded to any mitigation measures except winter-time shutdown, this could affect the parties’ ability to achieve the 50% reduction target. Pooling the species could also result in a 50% reduction in which the mortality of one species contributes almost entirely to the 50% reduction of the pooled species, while the mortality of other species remains unchanged.

(Feb. 27, 2007 SRC Call Meeting Note P14)

The Evolution of SRC Thinking on Pooling Species

The SRC discussed that interested parties could benefit on understanding the SRC’s thinking about a pooled-species approach and the implications of pooling for the Altamont-wide monitoring program. Members expressed concern that the pooled versus individual approach seems to have caused some confusion for the Board and others.

While the recommendation on sample size for achieving this margin of error is scientifically defensible, pooling the species is not the best approach from the SRC’s perspective. The SRC thinks that the best approach is represented in the “optimal program” (Jan 2007) which would measure the mortality change in individual species with a plus or minus 10% margin of error. The SRC’s decision to recommend a less optimal monitoring program as another option was prompted by cost considerations and in response to the County’s request….The sample size necessary to look at the four species individually would be more than 3000 turbines (as compared to 2000 turbines for the pooled species).

The SRC and monitoring team share significant concerns about the implications for individual species. For example, while it may be possible to reach a 50% reduction for pooled species, reaching a 50% reduction for red-tailed hawk as an individual species is unlikely. Reaching a pooled 50% reduction may have similar implications for other species as well as it does not indicate a 50% reduction for each. Finally, the monitoring results can demonstrate that an individual species’ mortality has been reduced, but results will likely not have the same degree of confidence in the change in mortality for another species (primarily because the certainty is affected by the number of incidents or fatalities).

SRC/MT Communication Process

(Feb 2008 SRC Meeting Summary P78)

The SRC and Monitoring Team members agreed to a communication plan to develop the next draft of the report, which emphasizes transparency as well as the separate roles of the two bodies. SRC members decided that Monitoring Team members can discuss data with SRC member Shawn Smallwood, who conducted the 2004 Altamont avian mortality study that formed the baseline. The Monitoring Team will log its calls and other discussion points, draft brief memos to the SRC describing their activities, and periodically brief the SRC in a public conference call on its progress, questions and statistical issues. The first SRC briefing will be scheduled for mid-March to consider statistical issues. In addition, citations will be given for assumptions. The documents can be linked from the SRC website.

(Feb 2007 SRC Meeting Notes P12)

  1. A MT representative to be present at SRC meetings on relevant issues
  2. MT to review draft SRC recommendation
  3. MT summarizes and submits disagreements
  4. SRC/MT meeting or conference call to resolve issues
  5. SRC produces final decision to MT via county

SRC Protocols: Regular Conference Call Meetings

(from Feb 2007 SRC Meeting Notes P12)

The SRC agreed to hold scheduled standing conference call meetings every 2-3 weeks to allow for timely response to issues. The conference calls will be regular meetings under the Brown Act, with agendized items for planned actions.

SRC Protocols

(from Feb 2007 SRC Meeting Notes P12)

  • Meeting Highlights to end with a list of SRC consensus agreements to document actions taken
  • SRC agrees to refer questioning parties to SRC agreements, documents & upcoming agenda items

Tiered Classification

(Dec 2006 Meeting Highlights P3)

The wind companies should use the June 2005 classification and professional judgment based on field experience and on-the-ground knowledge. If a wind company has reasoning to believe different turbines might be considered or certain turbines could create other problems, such as additional end points and the like, the company should approach the SRC with an explanation.


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