Attachment_4d_Clarifications_117_-_187_140P2123R0005_0004.pdf

NTCRA under CERCLA at El Capitan former waste dump Yosemite National Park Attachment 4d: Clarifications 161 - 187

Clarifications 161 – 187 for Solicitation #140P2123R0005

This document provides clarifications based on submitted queries.

Responses 1 – 69 are in Attachment 4a, posted with Amendment 1 on 6/20/23.

Responses 70 – 116 are in Attachment 4b, posted with Amendment 2 on 7/6/23.

Responses 117 – 160 are in Attachment 4c, posted with Amendment 3 on 7/17/23.

94 update: Regarding NPS’ response to Q. 94 requesting justification for the suggested use of Method SW8270D SIM instead of SW8310 for PAHs, EPA Method 8270 is recommended for PAHs (benzo[a]pyrene) because the gas chromatography/mass spectrometry method allows identification of chemicals through their mass spectra versus retention time. Identification by mass spectra is preferred because there are typically fewer false positives by EPA 8270 vs EPA 8310 (HPLC). Which method is required?

A. Method 8270 is required.

161. Tree Clearing: Is the contractor permitted to size-reduce and/or move downed trees and debris from DU areas to facilitate access and excavation? For larger fallen trees that would impact site access or soil removal activities, is the contractor responsible for cutting the trunk into smaller sections (please specify maximum size), or should large fallen trees be moved, to the extent practical, in a single piece to outside of the DUs or access paths?

A. The contractor may move downed trees and debris. To the extent possible, they should be moved in a single piece by an excavator. As part of the restoration of the area, distribute them across the DUs and access routes as a final step to “naturalize” these areas.

162. May the contractor cut dead or downed trees along the sides of the path to widen as necessary, including Black Oak trees? Black Oaks were noted at locations with branches hanging down within 7 to 8 feet of the ground. Equipment will need an overhead clearance of 12 to 14 feet. Please identify the location(s) where the tree and limb material should be disposed of.

A. The contractor may cut or moved dead and downed trees along the sides of the path, including downed black oak trees.

B. It appears your question is also asking about live black oak trees where you say “Black oaks were noted at locations with branches hanging down within 7 or 8 feet of the ground.” If live trees need to be limbed that will be approved only on a case-by-case basis by NPS VER, Forestry and the Tribal Monitor. Downed trees that are substantially cut or bucked should be loaded into a dump truck and disposed of at the El Capitan Woodlot or Foresta Woodlot.

Branches and other downed materials may be set aside and then distributed across the margins of the access route as a final step to “naturalize” these areas post-restoration.

163. Tree Clearing: If NPS has clearing personnel already trained on how to take down timber in the park can they take the trees down per the winning contractor’s plan after award but prior to mobilization?

A. It is the contractor’s responsibility to execute tree removal. If there is a complex scenario for a tree removal, the contractor may consult with NPS forestry.

164. Is there a maximum diameter for potential tree removal? For trees over a specific diameter or height, would Yosemite NP personnel be responsible for felling the tree, or would the contractor be responsible?

A. Black oak trees of any size class should not be removed. Conifers, such as Ponderosa Pine and Incense Cedar, may be removed up to 20” DBH in consultation with NPS VER representative. Conifers over 20” DBH ordinarily require additional compliance and should be considered on a case-by-case basis. Very large trees should be avoided. The Contractor will be responsible for all approved tree removals, though they may consult with the Park Forestry team if there is a complex removal.

165. Will the government conduct a survey for selective cutting of trees within the excavation area? If not, who is responsible for determining which trees can be removed and which one cannot be removed?

A. The contractor will be responsible for flagging conifer trees they propose to remove and then an NPS VER representative will approve or deny this request. Black oak trees should not be removed.

166. Is there an excavation boundary regarding proximity and depth for trees within the excavation area?

A. The excavation boundary will be incorporated in the survey performed by park VER team.

167. DU 11 and DU 12 were noted to have Black Oak trees directly adjacent to or in the DUs.

DU limits were not shown in the field. Will the NPS identify an exclusion zone to prevent damage to the root systems and Black Oak trees?

A. It is the opinion of NPS VER that these DUs should be minimally excavated, so with a mini excavator, soil knife or by hand as they are within the driplines of mature black oaks that must be retained. Protecting these roots is of extreme importance. NPS VER can provide guidance Pre-Construction. (see Q 165).

168. Please provide information about planned road construction and other projects for 2024 and 2025 that may impact the traffic routes.

A. Currently there are no major planned projects in 2024-2025 that will impact access routes for this task. There is now a 30’ limit on Sentinel Bridge; vehicles longer than 30’ will have to continue to Curry Village to access Northside drive.

169. SOW Section 7.5: Please provide the park guidelines for trail restoration, including specifications for trail construction and trail material. Please clarify to what extent the existing trail and former dump road are to be protected and restored.

A. The existing trail should be restored to a condition similar to what it was pre-construction.

This trail has variable conditions as it traverses the path along the DUs. The former Dump road should be restored as a pedestrian path following construction. The contractor will have to coordinate with Trails Supervisor David Kari David_Kari@nps.gov before construction.

mailto:David_Kari@nps.gov

170. NPS indicated that the staging area can be/will be cleared for use during the project. Will NPS clear the area or will the contractor need to perform this task?

A. The staging area at the entrance to the access road is currently relatively clear and it will be the contractor responsibility to ensure area is clear at time of mobilization.

171. Will there be an assigned project parking area for crews?

A. The park would consider reserving limited parking at the parking spur across from the El Capitan picnic area, the parking spur east of El Capitan Picnic area, and/or incorporating crew parking into the northside drive lane closure.

172. Can the area at Northside Drive and project access be used as a stockpile location for loading material into highway trucks?

A. Yes, but this area should be minimized and restored post removal action.

173. WP Attachment 2a: Section 4.3.2 and Section 4.7 lists SVOCs for characterization sampling, but Table 5 lists PAHs to be analyzed and not SVOCs. Please confirm SVOCs is the correct analyses.

A. SVOCs is the correct analysis for characterization sampling.

174. Work Plan, SAP Section 4.3.2, Table 2 lists a total of 261 discrete samples. The total quantity of discrete samples (including field replicate samples) listed in Table 5 is 302. Please confirm quantity of discrete samples.

A. The total of 261 samples given in Table 2 is specific to the estimated stockpile volumes given. Table 2 contains an error; the correct total is 287. The total of 302 samples in Table 5 includes stockpile samples plus field replicates; the number of field replicates depends on the actual number of discrete samples. For planning purposes, assume 302 soil samples.

175. SAP Attachment 2a, Section 4.6.1: Table 5 does not account for field duplicates, MS/MSD, or trip blanks. Shouldn’t this be added to the analyses and sampled in the frequency outlined in Section 4.6.1, Quality Assurance/Quality Control?

A. (Assuming that this question refers to SAP Table 5; there is no SAP Attachment 2a.).

Field replicates are proposed (SAP Section 4.6.1) and are included in Table 5. MS/MSD is not a field sample, so isn't listed in Table 5. The number of trip blanks depends on the number of containers/shipments, which cannot be known at this time.

176. WP Attachment 2a, Section 4.7: For Method 8290A, please confirm that the list of analytes is the following:

• 1,2,3,4,6,7,8‐HPCDD (35822‐46‐9)

• 1,2,3,4,6,7,8‐HPCDF (67562‐39‐4)

• 1,2,3,4,7,8,9‐HPCDF (55673‐89‐7)

• 1,2,3,4,7,8‐HXCDD (39227‐28‐6)

• 1,2,3,4,7,8‐HXCDF (70648‐26‐9)

• 1,2,3,6,7,8‐HXCDD (57653‐85‐7)

• 1,2,3,6,7,8‐HXCDF (57117‐44‐9)

• 1,2,3,7,8,9‐HXCDD (19408‐74‐3)

• 1,2,3,7,8,9‐HXCDF (72918‐21‐9)

• 1,2,3,7,8‐PECDD (40321‐76‐4)

• 1,2,3,7,8‐PECDF (57117‐41‐6)

• 2,3,4,6,7,8‐HXCDF (60851‐34‐5)

• 2,3,4,7,8‐PECDF (57117‐31‐4)

• 2,3,7,8‐TCDD (1746‐01‐6)

• 2,3,7,8‐TCDF (51207‐31‐9)

• OCDD (3268‐87‐9)

• OCDF (39001‐02‐0)

A. That is the list of analytes.

177. Are composite mats/plywood required for access by tracked equipment?

A. No, however, anywhere the contractor creates an access route to and from a DU over vegetation, the vegetation should be salvaged in large plugs using an excavator, set to the side, watered frequently, and then replaced as soon as possible within the access route.

178. Installation of mats/plywood require a level surface in order to work properly. Is the associated grading acceptable on the access road and meadow?

A. Grading outside of the DUs is not acceptable.

179. If we plan to use wheeled vehicles on the access road, does the entire road require track mats?

A. No, however the wheel tracks will require rehabilitation to trail specifications in consultation with Dave Kari, NPS trails supervisor.

180. Questions 20, 21, 112, and 113 discuss ISM sampling for expanding the excavation. If the ISM results from a DU show an exposure area exceeds the removal goals, the excavation will be continued. For DUs that exceed the RG, the results of ISM sampling will not be able to identify which portion of the DU causes the exposure area to exceed the RG. Should split samples from each of the 30 points that comprise the ISM increment be collected and put on hold so that if the exposure area exceeds the RG they can be analyzed to determine what area has the highest concentrations, and is causing the ISM sample to fail the RGs?

A. Collect the ISM samples and composite per the workplan but as suggested archive a split of each of the 30 points samples. Submit ISM composite for analysis. If the ISM composite exceeds the RG then analyze the 30 individual point samples for the chemical(s) that exceed the RG.

181. Attachment 4a question 40 regarding Mariposa County as agency for allowing injection of amendments has not been completely addressed. Has NPS determined if Mariposa County will approve injections?

A. The work is being overseen by DTSC. A permit to allow the injection of amendments will be required from Mariposa County.

B. NPS has not determined if Mariposa County will approve injections. YOSE/El Capitan’s Workplan and SAP received approval from CAL/EPA-DTSC who are the regulatory authority for the site.

182. Can the contractor have a fuel storage tank at the staging area?

A. Fuel storage will require containment within a flammable proof locker, secondary containment for the tank within the locker, and a spill response kit. A fire hydrant will need to be located within 100’ of the fuel tank storage. A plan for fuel storage and containment needs to be approved by the park prior to delivery to site.

183. Regarding the response to Clarification 71, please clarify whether hexavalent chromium is a required analyte and for which sample types. It is not included in Table 5 of the SAP.

A. Hexavalent chromium is not a CoC, so is not a required analyte.

184. Will workers lodging off-site be required to obtain daily or annual passes to access the Park?

A. No, workers associated with this project will have a gate entry pass provided by the park.

185. Amendment 1 Q #11 says the park will consider closing the left lane of the northside drive adjacent to El Capitan FEDA for the purpose of staging. Traffic control will be needed. As part of implementation of lane closure during loading of transport trucks, will the NPS provide traffic control? If the park will not provide traffic control, does a traffic control plan need to submitted and approved by the park for approval? Will the park require an easement permit? Do traffic control signs and cones need to be setup and removed on a daily basis? Will flaggers be required?

A. NPS will not provide traffic control. The contractor will need to prepare and submit a traffic control plan to the park for approval. Flaggers are typically not required for two lane one-way roads that are restricted to one lane.

B. See SOW Section 9.12 and refer to NTCRAWP Appendix B for additional transportation requirements, including that the Contractor will develop a within-Site traffic plan that will minimize disturbance between areas to be addressed under this removal action.

186. Soil Sampling Requirements. Please clarify the requirement for the analysis of Pentachlorophenol (PCP). Analysis of PCP, a wood preservative for power line poles and fences and a chlorinated herbicide, is not required in Section 4.3.2 of NTCRAWP Sampling and Analysis Plan for stockpile soil disposal but is required in Table 5 (Disposal of Soil).

A. Analysis for PCP is included in Table 5 based on the assumption that a disposal facility will require analysis for PCP. The selected disposal facility may or may not actually require analysis for PCP.

187. Excavations at the Designated Units and the creation of access for contractor equipment will generate a significant volume of green waste. Will the NPS want this material disposed of off-site or does the NPS have a program to dispose/process the material in the park?

A. Large wood debris may be disposed of at the El Capitan Woodlot or Foresta Woodlot at the direction of Park Forestry Team. Green Material may be utilized on site by the VER team as part of their duffing of disturbed areas. If there is still excess material, there may be a possibility of building burn piles at the direction of the Park. The park does not anticipate a need to haul green waste out of the Park as part of this project.