JUSTIFICATION FOR FAIR OPPORTUNITY EXCEPTION

Sulphur Bank Mercury Mine Residential Remedial Action

In accordance with Revolutionary FAR Overhaul (RFO) 16.507(b)(2)

In accordance with the RFO 16.507(b)(2), the proposed contractual action is pursuant to the statutory authority of 41 U.S.C. 253(c).

I. Identification of the agency and the contracting activity and specific identification of the document as a "Justification for an Exception to Fair Opportunity."

Contracting Office: Region 9 Program Name: Superfund and Emergency Management Division (SEMD) National Priorities List (NPL) Site: Sulphur Bank Mercury Mine Contract Type: Cost Reimbursement Contract Suite: Design and Engineering Services (DES) Requisition No. PR-RAF9-26-00139 Period of Performance: Base Period - June 10, 2026 – June 09, 2027 (12 months)

Option Period 1 – June 10, 2027 – December 10, 2027 (6 months)

II. Name and/or description of the action being approved.

Design and Engineering Services (DES) Task Order for Sulpher Bank Mine, Clearlake Oak, CA to provide continued expert technical assistance (TA) in overseeing the implementation of the residential soils portion of OU-1 of the Sulphur Bank Mercury Mine Superfund Site (SBMM or Site) remedial action.

III. A description of supplies or services required to meet agency needs (including estimated value).

The scope of this sole-source contract is to provide continued expert technical assistance (TA) in overseeing the implementation of the residential soils portion of OU-1 of the Sulphur Bank Mercury Mine Superfund Site (SBMM or Site) remedial action. This work is a continuation of the activities completed by EA Engineering Science and Technology under DES Task Order 68HE0924F0079. To ensure the efficient and effective implementation of the remedial design prepared by EA in 2025, this task order would provide USEPA with the engineer of record’s expertise to observe key field activities, review requests for information from the construction contractor, prepare modifications to the design drawings and specifications if required, and document where and why work was performed in a manner different from the final design.

The Task Order award value is $650,000.

IV. Identification of the exception to fair opportunity (see paragraph (b)) and the supporting rationale, including a demonstration that the proposed contractor’s unique qualifications or the nature of the acquisition requires use of the exception cited.

RFO 16.507-6(a) requires an ordering activity to justify its actions when fair opportunity is restricted. The specific circumstance that justifies restriction for this acquisition is RFO 16.507-6(b)(2), only one awardee is capable of providing the supplies or services required at the level of quality required because the supplies or services ordered are unique or highly specialized.

Background:

Sulphur Bank Mercury Mine (SBMM) is a 160-acre former cinnabar mercury mining site located on the eastern shore of the Oaks Arm of Clear Lake, approximately 70 miles northwest of Sacramento in Lake County, California. The mine operated from 1865 to 1957, utilizing both underground and open pit mining technologies. SBMM consists of mine tailings and waste rock and a flooded open pit mine (the Herman Impoundment). Approximately two million cubic yards of waste rock and low-grade ore remain onsite and contain high levels of mercury, arsenic and antimony. The Herman Impoundment is filled with water to a depth of 90 feet and is located approximately 750 feet east of Clear Lake, which is separated from the impoundment by an earthen dam composed of waste rock material and in-place bedrock. SBMM was placed on the Superfund National Priorities List (NPL) in August 1990 due to the impact of site contamination on the residents near the mine and wildlife in the vicinity of Clear Lake. The Elem Indian Colony (EIC) utilizes the land on and near SBMM for traditional cultural activities. Clear Lake is the source of drinking water for approximately 4,700 people.

After adding SBMM to the NPL, the EPA pursued emergency cleanup measures at SBMM. These measures included regrading and soil cover of the Herman Impoundment dam; residential soil removal at the EIC; a stormwater diversion pipeline to limit inflow into Herman Impoundment; excavation of soils along Sulphur Bank Mine Road and BIA 120. The CERCLA work on SBMM is predominantly being conducted by the EPA as lead agency, in consultation with the California Department of Toxic Substances, the Regional Water Quality Control Board, and EIC.

SBMM has been divided into three operable units (OUs):

• OU-1 encompasses 160 acres of the former mine itself consisting of the Waste Rock Dam (WRD), waste piles; Herman Impoundment; and the off-mine impacted soil areas on the EIC and to the south of the mine.

• OU-2 includes Clear Lake Oaks Arm and its sediments.

• OU-4 includes the wetlands to the north of mine and the study area to the east and south of the mine.

A Record of Decision was signed in November 2023 selecting the cleanup approach for Operable Unit 1.

EA was contracted by USEPA to prepare the engineering design package for the residential soils cleanup portion of the OU-1 remedy. The 100% design package, including detailed drawings and specifications defining how to perform the required remedial action for this portion of the remedy, was delivered to EPA in October 2025. The activities described in EA’s design package are expected to be implemented by a separate remedial construction contractor beginning in summer/fall 2026. This task order will ensure that the engineer of record who evaluated, designed, and sealed (stamped/certified) the remedial design package to be implemented is available to the USEPA to oversee the design’s execution, evaluate any needed changes or revisions, and ensure that their design is implemented in accordance with the defined requirements.

EA has the unique qualifications and necessary knowledge, staff, and experience to complete this work at the level of quality required as it currently provides the services described herein for the Sulphur Bank site. EA has participated in site activities since being hired as a primary contractor for TO 0036 (68HE0919F0114) under RAC III in 2019. Most critically, EA employes the engineer of record who is responsible for the design package that EPA is seeking to have implemented. In order for this design to be modified, such modifications require the review and approval of the engineer of record or another engineer who was “substantially involved” in the development of the design. Should the construction contractor encounter conditions in the field that differ from the expectations and understanding of the EPA and EA at the time of the development of the design, the engineer of record’s services is required to evaluate and certify the necessary design modifications. Should the construction contractor require direction as to how to implement particularly complex and challenging elements of the design, EA has the engineering personnel responsible for the development of the design and therefore is uniquely qualified to provide that service.

EA is uniquely qualified to provide the site-specific subject matter expertise to meet U.S. EPA’s urgent time needs for overseeing implementation of the residential design in order to complete the remediation of the affected residential units at the Sulphur Bank Mine site. The SBMM site results in uncontrolled exposure to site-related contaminants for multiple user groups. This exposure results in unacceptable risk greatly exceeding EPA’s risk management range. This risk is greatest for the residents nearest the mine who live continuously on site-impacted soils. EPA needs to urgently move forward with the implementation of the design prepared by EA under task order 68HE0924F0079. The only alternative to employing the engineer of record who prepared the design would be to transfer responsibility for oversight to an external engineering firm. This would require month-long reviews, verification, and possible revision before being re-stamped by a new engineer of record. Such a takeover of the design would result in unacceptable delays, extending the period during which the affected community is exposed to harmful levels of site-related contamination. EPA is currently in the contracts acquisition process for the construction contractor with the goal of beginning remedial action in the summer/fall of 2026. Also, if take over of EA’s design was pursued, additional costs could be expected to range in excess of $200,000, which would constitute a greater than 30% increase in cost relative to the government estimate for the required oversight support services.

The benefits of retaining EA Engineering as the support contractor for the identified work include, but are not limited to, greater effectiveness in the construction of the Sulphur Bank Residential Remedial Design as a result of the oversight of construction activities by the engineer of record and their support personnel who have the greatest knowledge and expertise in the approved design package; significantly accelerated ability for EPA to execute its core mission of protecting human health as required under the Comprehensive Environmental Response Compensation and Liability Act; more accurate and rapid turnaround of the construction contractor’s requests for information and other potentially required design modifications; and reduced cost to the government by eliminating the need for an external engineer to review, verify and re-stamp the design package that EA’s engineer has already stamped.

V. A determination by the contracting officer that the anticipated cost to the Government will be fair and reasonable.

The Contracting Officer will evaluate the pricing for the order to determine that the costs to the Government are considered fair and reasonable. The pricing is expected to be based upon similar labor rates that have already been incorporated into the current task order 68HE0924F0079 for which EA is the primary contractor. These rates/costs were previously determined to be fair and reasonable. Furthermore, the contractor has agreed to ceiling labor rates at the IDIQ level for each contract year under RAF Contract 68HE0318D0005. The Contracting Officer and the Program Office will also review the anticipated level of effort to ensure that it is consistent with the work required by the follow-on requirement. During performance, the labor hours incurred by the contractor will be subject to surveillance by the Contracting Officer's Representative (COR). Travel Incurred by the contractor will be reviewed by the government and will be reimbursed only for actual expenses incurred that are determined to be reasonable and within the limitations of the Federal Travel Regulations (41 Code of Federal Regulations (CFR}, Chapters 300 through 304).

VI. Any other facts supporting the justification.

N/A

VII. A statement of the actions, if any, the agency may take to remove or overcome barriers to competition.

To remove or overcome any barriers to competition, the EPA will continue to monitor the SF330s for contactors experience in overseeing the implementation of a design package for remediation of contaminated residential soils in circumstances similar to the project, including culturally sensitive soils, requiring care towards compliance with National Historic Preservation Act, including development of on-site soil borrow areas, rural roadway improvements and other pertinent expertise. Additional sources for market research included SAM.gov, CPARS and internet searches of firm sites and relevant terms.

VIII. Contracting Officer’s certification that the justification is accurate and complete to the best of the contracting officer’s knowledge and belief.

Digitally signed by MENA

MEDEIROS

Date: 2026.05.05 06:36:06 -07'00'

Mena Medeiros, Task Order Contracting Officer

IX. Evidence that any supporting data that is the responsibility of technical or requirements personnel (e.g., verifying the Government's minimum needs or requirements or other rationale for an exception to fair opportunity) and which form a basis for the justification have been certified as complete and accurate by the technical or requirements personnel.

Digitally signed by CARTER JESSOP Date: 2026.05.04 21:12:05 -07'00'

Carter Jessop, Remedial Project Manager

X. Written determination by the approving official that one of the circumstances in RFO 16.507(b)(1) paragraphs (b)(1) through (6) applies to the order. Approval per RFO 16.507-6(e)(2).

Rede Shifferaw, Region 9, Acquisition Manager (RAM)

MENA MEDEIROS

I. Approvals (CO to fill out) Reviews and approvals must be performed in accordance with EPA Acquisition Guide Section

1.6 Attachment A and FAR 16.505(b)(2)(ii)(C).

In accordance with FAR 16.505(b)(2)(U)(D), within 14 days after placing the order, the Contracting Officer will publish a notice 1n accordance with FAR 5.301 and make publicly available the Justification at www.fedblzopps.gov and on the website of the agency, which may provide access to the justification by linking to www.fedblzopps.gov, for a minimum of 30 days.

In accordance with FAR l 6.505(b)(2)(ii)(C), I certify the rationale and supporting data which forms the basis of this justification as complete and accurate. As such, this justification is approved.

Mena Medeiros Task Order Contracting Officer

R9-MSD-CB

Date

Rede Shifferaw Regional Acquisition Manager

R9-MSD-CB

Date http://www.fedblzopps.gov/ http://www.fedblzopps.gov/