SDG&E Response to Data Request Number 1

SUNRISE POWERLINK PROJECT(A.06-08-010)

SDG&E Response to Data Request Number 1

Submittal 2 of 3, October 31, 2006

General

GEN-1:In order for the EIR/EIS team to be aware of access problems for surveys or site visits, please provide a listing of property owners (including phone numbers) along the Proposed Project route and SDG&E alternatives retained in the PEA, where SDG&E does not have right-of-entry.

Response:Attachment GEN-1 includes a list of property owners, with phone numbers, addresses and assessors parcel numbers (APN), for the Proposed Project and alternative routes in the Coastal Link and the Desert Link (including the ABDSP Alternative) indicating where SDG&E does not currently have right-of entry (ROE). SDG&E was not able to obtain phone numbers for all property owners. Also attached is an ROE status list for that portion of the project (from N12 to N1) for which the Imperial Irrigation District is doing ROE. We will continue to update the CPUC as ROE status changes or missing phone numbers are added.

GEN-3:a. Please provide GIS files including all existing transmission line structures within the proposed ROW (current data includes only structures to be added or removed).

Response:a: Due to further interpretation of all existing transmission line structures with the proposed ROW, the completion of this data request was emailed out on Wednesday October 25th to the CPUC and Aspen recipients. This pertains to ALT-37 as well.

PROJECT DESCRIPTION

PD-8:There are two underground segments identified for the Proposed Project. Some of these segments would be located in urban streets that likely have other existing underground utilities. Please identify the separation required between the transmission line duct bank and other buried utilities (e.g., natural gas or water pipelines), especially those that operate at high temperatures. Please identify areas where the Proposed Project would run parallel or perpendicular to these high temperature substructures. Are there other instances where the SRPL underground lines would require additional separation distances (e.g., where corrosion of parallel pipelines could occur)?

Response:The underground routes for the Sunrise Powerlink (SRPL) run parallel to and cross other utilities. Identified utilities are gas, water, sewer, drainage, telecommunication, street lights, signal lights, and electric distribution. SDG&E will design and route all underground transmission facilities in compliance with CPUC GO-128. Clearances and depths will meet requirements set forth with Rule 33.4 of GO-128. At this time, no utilities that operate at high temperatures have been identified. The ideal clearances to be maintained with other utilities are as follows:

2 feet for perpendicular crossings

5 feet for paralleling non-electrical utilities

10-20 feet for paralleling electrical utilities depending on the voltage level

In areas where there are space limitations, clearances to utilities may be less then ideal. It is our experience that maintaining a minimum clearance of 12 inches to crossing utilities and a minimum of 24 inches to paralleling non-electricalutilities is a safe and adequate practice. Preliminary engineering has not shown any areas where the SRPL underground route would require additional separation distances. In regards to potential corrosion, the above clearances are considered adequate to prevent corrosion of adjacent utilities. However, SDG&E will coordinate with affected utilities to confirm that corrosion will not be an issue.

In addition, the final plan & profile layouts of all SRPL underground routes will be submitted for review to other utilities, cities and other local jurisdictional governments. Upon their review, SDG&E will make any additional adjustments to ensure that all utilities agree with the designed clearances, thus insuring that the new underground transmission lines will not have any negative affects on the existing utilities.

ALTERNATIVES

The EIR/EIS Team is evaluating a wide range of alternatives to the Proposed Project. No decision has been made as to which specific alternatives may be carried forward for analysis in the EIR/EIS; however, additional information is required in order for us to complete the screening process allowing this determination to be made. Also, we are requesting “preliminary engineering” on certain components that we believe are almost certain to require EIR/EIS analysis. For the following questions, we will first state the alternative for which we require information, then present the question(s) themselves.

Alternatives Avoiding Anza-BorregoDesertState Park by Collocating with Segments of the SWPL

Any alternative that avoids ABDSP requires collocation with the existing 500 kV SWPL for a longer segment than that proposed by SDG&E in its Proposed Project route. The following questions are presented in order for us to clearly understand SDG&E’s stated concern about the reliability of this collocation.

ALT-1a. Provide references togeneral NERC and WECC criteria for reliability that apply to 500 kV transmission lines and requirements related to separation of parallel 500 kV transmission lines from each other.

Response:a. SDG&E is required to plan its transmission system to the reliability criteria of NERC/WECC and the CAISO. The NERC, WECC and CAISO planning standards generally provide that if a planned transmission circuit is to be adjacent to another transmission circuit, regardless of operating voltage, a case-specific analysis is required to determine whether the proximity of the circuits, and the geography that the adjacent circuits traverse, dictates specific mitigation measures for common mode contingencies (up to and including a determination that such proximity would constitute a violation of the planning standards[1]). An exception is made where multiple circuit towers are used over short distances (e.g., station entrance, river crossings).[2]

The case-specific analysis takes into account the probability of occurrence of an outage of two adjacent circuits on separate towers, line design, the distance over which the two circuits are adjacent to each other, location, environmental factors, outage history of existing circuits, operating guidelines and separation between the circuits.[3] In general terms, if twocircuits on separate towers are adjacent foronly a short distance; or if thegeography over which the two circuits are adjacent is not subject to wildfires, lightning strikes or other common mode contingencies; then the likelihood of the common mode contingency is considered improbable (sometimes called “non-credible”) and no mitigation is required.

On the other hand, if two circuits on separate towers are adjacent for a longer distance; or if the geography over which the two circuits are adjacent is subject to wildfires, lightning strikes or other common mode contingencies; then the common mode contingency is considered “credible” and mitigation, including the possibility of “Planned/Controlled” load drop, is required.

Applying the above reliability criteria to the San Diego-Imperial Valley corridor suggests that anew line could be constructedon separate towers adjacent totheexisting500 kV Southwest Powerlink only forashort distance without violating applicable reliability criteria or requiring a "Planned/Controlled" load drop in the event ofacommon mode contingency event. If the two circuits were adjacent for longer distances, thenitmaybe necessary to implement "Planned/Controlled" load drop in order to mitigate any unacceptable thermal line loadings or voltages that result because the distances that are practically available if the governinggeography would make the facilities subject to common mode contingency events.

The native vegetation in rural San DiegoCounty is prone to periodic wildfires, abetted by hot, dry “Santa Ana” winds blowing west from the desert – the same winds that often bring the weather triggering the system peak. These fires generate intense heat and smoke due to the natural creosote laid down by generations of decaying brush. The smoke can trip a transmission line, even if the fires are not directly under the lines. There have been 46 outages of the Southwest Powerlink in the last 15 years, with 22 being fire-related on the San DiegoCounty portion of the Southwest Powerlink. Since 1990, there have been two lightning strikes that tripped the Southwest Powerlink. These strikes also occurred on the San DiegoCounty portion of the Southwest Powerlink.

b. Explain why there is variation among WECC-approved parallel 500 kV projects (e.g., Devers-Palo Verde No. 2 would have a 130 foot separation from Devers-Palo Verde No. 1, but Path 15 [Los Banos-Gates 500 kV] was constructed at "a minimum of 2000 feet" from the original 500 kV line).

Response:b. Each entity proposing a transmission project must design the project to address the applicable conditions described in SDG&E’s response to question ALT-1.a. The SCE Palo Verde – Devers No. 2 line is being designed with a load dropping remedial action scheme for loss of both Palo Verde – Devers No. 1 and No. 2 lines. Because of the significant benefits of the Sunrise Powerlink project is improved system reliability no load dropping scheme is proposed for simultaneous loss of both the Sunrise Powerlink and the Southwest Powerlink. Actual line separation will vary depending upon the specific situation. SDG&E has contacted SCE and PG&E for additional information on their transmission projects, but as of Thursday, October 26, 2006, has not received a response.

ALT-2Have WECC, CAISO, or STEP proceedings defined specific reliability criteria for a second 500 kV line parallel to the SWPL? If so, please provide such criteria, along with references to documents in which they were presented.

Response:The Southwest Transmission Expansion Plan (STEP) group has no reliability criteria of its own. The STEP study group used the WECC reliability criteria for their studies. The WECC and CAISO have reliability criteria that would apply to a second 500 kV line parallel to the Southwest Powerlink (see SDG&E’s response to question ALT-1), but they have not defined any specific reliability criteria designed especially or exclusively for a second 500 kV line parallel to the Southwest Powerlink. Attachment ALT-2provides comments of the CAISO regarding the alternative route proposals submitted by SDG&E.

ALT-5Please provide a copy of the CEQA and NEPA environmental documentation that was prepared when the SWPL was constructed.

Response:Attachment ALT-5 includes the APS SDG&E Interconnection Project Environmental documents. There are 5 documents titled:

oFinal Environmental Document,

oSupplement to the Draft Environmental Document

oEnvironmental Study Phase II Corridor Studies Addendum

oEnvironmental Study Phase II Corridor Studies Addendum Link 167

oEnvironmental Study Phase II Corridor Studies Addendum Link 87 and 88

ALT-6SDG&E has previously pointed out “pinch points” where environmental constraints exist along the SWPL corridor. Please answer the following questions about these locations:

a. The Jacumba Wilderness appears to end north of the Mexican border. Given the existence of the Jacumba Wilderness and the Campo Reservation, would it be possible to install a new set of towers south of the existing SWPL and outside of the Wilderness Area, but then use those new towers for the existing IV-Miguel circuit? The existing SWPL towers could be used for the new IV-Central (or other endpoint) circuit. This should allow for avoidance of critical land uses (i.e., the Jacumba Wilderness) without requiring crossings of the 500 kV lines. Please comment and confirm that this would be possible.

Response:a. Based on mapping and other information received from the BLM after the PEA filing, the southern boundary of the Jacumba Wilderness is approximately 3 miles north of the existing Southwest Powerlink (SWPL) corridor. This separation would provide adequate space to locate a transmission line north of SWPL without encroaching the wilderness area.

b. In PEA Supplement map Attachment ALT 1, SDG&E pointed out “Indian land” as a pinch point in the vicinity of the Campo Reservation. Similar to item a above, could this land be avoided by installing the new towers south of the existing SWPL?

Response:b. At the Campo Indian Reservation, the existing SWPL transmission line runs along the southern reservation boundary within an easement, 330 feet in width. There is limited space to the south of SWPL as the U.S./Mexico border is approximately 2000 ft. to the south. Also, between SWPL and the border, there are several homes in this area that would likely have to be relocated to accommodate a new transmission right-of-way.

The SWPL transmission line could be relocated to new 500kV towers placed a minimum of 130 ft. (center-to-center) south of the existing towers. The existing SWPL towers could then be used to support the conductors for the new transmission line, but may require approval by the Campo Indian Tribe and an amendment of our existing easement. Although this configuration does not avoid the Campo Reservation, it would prevent two (2) 500kV transmission crossings.

The new towers proposed for the Sunrise Powerlink will have the same appearance as those used for the Southwest Powerlink, but will be designed to support the proposed conductors. If the existing SWPL towers are used to support the new Sunrise Powerlink 500kV transmission line, the existing SWPL towers will likely require modification to increase their structural strength. This is due to the fact that the SWPL towers were designed to support a conductor configuration with a slightly smaller cross sectional area than what is proposed for the Sunrise Powerlink. Any structural modifications would be completed in the field during construction. Another issue that would be of concern is duration of outages required to relocate SWPL. This work would require outages that could last several days.

Alternatives Through ClevelandNational Forest

The most feasible non-ABDSP routes that were considered by SDG&E appear to be Alternatives C and D, which both follow existing 69 kV transmission lines and pass through portions of the ClevelandNational Forest. Answers to the following questions will allow us to understand these routes and their potential constraints.

Substation Options. The Proposed Project includes a 500/230 kV substation at a point approximately 30 miles from the eastern border of San DiegoCounty. We are evaluating several potential locations for a 500/230 kV substation at similar points along an alternative route that would parallel the SWPL. These substation locations could be used in conjunction with portions of the C, D, and C-D alternative routes (as well as other routes developed by the EIR/EIS Team). Converting the project to a 230 kV line near the SWPL would allow greater flexibility in line siting when designing a north-south transmission line route that would connect with the Proposed Project route to the north. Please provide the information requested below for each of the 500/230 kV substation options described.

ALT-10:Construction of a New 500/230 kV Substation after following the SWPL into central San DiegoCounty. Please provide preliminary engineering using a feasible low profile design (describing site size required, equipment needs, and comments on the feasibility of a substation at these locations) for a 500/230kV substation that could be located at one of the following sites:

a. The Barrett Substation is surrounded by undeveloped land and is relatively flat. There are residences west of the substation, but not nearby to the north or south. Please provide preliminary engineering (describing site size required and equipment needs) for the Barrett Substation if that facility were to be expanded to a 500/230kV substation.

b. East of the intersection of Hwy 94 and Barrett Lake Road, where the SWPL crosses Hwy 94, there is a Caltrans yard. Identify a site that SDG&E believes to be the most appropriate for a 500/230 kV substation in this vicinity.

c. Could a substation be located adjacent to the SWPL on BLM land, at a point generally southwest of the Barrett Substation and about 3 to 5 miles west of Barrett Lake Road? Identify a site that SDG&E believes to be the most appropriate for a 500/230 kV substation in this vicinity and adjacent to the SWPL.

d. Along or just north of the SWPL corridor, south of the Cameron substation. Identify a site that SDG&E believes to be the most appropriate for a 500/230 kV substation in this vicinity.

e. Could the Loveland Substation (south of Alpine) be expanded to be a 500/230 kV substation? Please provide the size of the parcel that SDG&E owns, a detailed topographic map and an aerial photograph of the site.

Response:Attachment ALT-10, ALT-19 provides a comparative matrix of the various development constraints associated with each of the identified potential alternative substation sites. Additionally, the general arrangement of the 500/230 kV substation has been overlaid on the aerial imagery and topographical contours to assess approximate limits of grading. The supplemental graphics depict the limits of grading for each of the potential alternative substation sites identified, excluding the Loveland and Barrett Smith (CalTrans Yard) alternative sites due to their overall infeasibility as a result of high development constraints.

ALT-11:How wide are the existing SDG&E rights-of-way (ROWs) along the "D" alternative route, "C" alternative route and "C-D" segment alternative route? If the ROW widths vary along the routes, please provide the widths by milepost in a table, with an associated map showing milepost locations.

Response:Attachment ALT-11 includes a map and two tables. The map depicts the existing SDG&E ROW along the existing SWPL transmission line, and the C, C-D, and D alternative routes. The first table includes structure information for in this area for SDG&E’s existing ROW, and the second table depicts the existing SDG&E ROW widths along with assigned mileposts.

ALT-13:The EIR/EIS Team is looking at all alternatives between the SWPL ROW and the proposed ROW in the Ramona area. Please provide detailed environmental information on the following east-west corridors: B-C corridor and C-D corridor in the same level of detail as provided for other alternatives identified in tables on PEA p. 3-11 to 3-13.

Response:The table below identifies the B-C and C-D corridors detailed environmental analysis information. The table below describes the key routing considerations. This information was previously provided in the Sunrise Powerlink Routing and Siting Study in Appendix B attached in Table 3, along with the complete environmental analysis information for those corridors.