Bishop Well Control Incident (last update 6/4/2025, 6:00 PM)

Remediation for the Bishop incident is a multi-step, multi-faceted process. The operator, Chevron, is responsible for all clean up activities. That work is regulated and enforced by the Energy and Carbon Management Commission (ECMC). ECMC holds operators accountable to the state of Colorado’s strict and protective remediation standards. Specifically, the spill of exploration and production waste is under the jurisdiction of ECMC in accordance with the state’s Oil and Gas Conservation Act. Other state regulatory agencies, local County authorities, and federal agencies also play a regulatory or enforcement role.

The first step was to contain the blowout. Containment was achieved within five days and was led by the Unified Incident Command. (The Unified Incident Command team, composed of Weld County first responders, Galeton Fire Protection, Chevron, and US Environmental Protection Agency (EPA), oversaw the initial emergency response to the incident. Contractors working for Chevron successfully stopped fluid flow from the well on 4/10/2025. On 4/11/2025 the response team declared the well control incident successfully secured; secure is defined as a confidence in the containment.)

That declaration returned the Bishop well and the spill of exploration and production waste to the jurisdiction of ECMC. In accordance with state rules, Chevron produced an Environmental Sampling and Analysis Plan (ESAP) that ECMC expert staff approved and posted on 4/17/25. An ESAP is a scientific and technical plan for the collection and chemical analysis of environmental samples for surface water, groundwater, and soil sampling prepared specific to this incident. Then, on 4/24/25 ECMC posted Chevron's Analytical of Source Material documentation. The document includes test results of oil samples taken on 4/8/25. The samples were taken from two locations near the source of the spill: one sample was taken from the pad of the incident and one from an emergency diversion ditch adjacent to the pad. Next, on 5/1/2025 ECMC approved Chevron’s initial Investigation/Remediation Workplan. ECMC requires operators to submit an Investigation/Remediation Workplan for any spill or release of waste for which cleanups and remediation is anticipated to take longer than 90 days. The Workplan describes the ways in which impacts from the incident will be remediated and how the remediation will be monitored and validated.

The workplan includes a timeline of remediation. Chevron anticipates that remediation will be completed by April 2030. Environmental remediation can take a considerable amount of time due to several factors, including the complexity of contamination, the scale of the affected area, the chosen remediation methods, and the need for long-term monitoring.

Attached to the Form 27 Workplan are four separate Sampling and Analysis Plans (SAPs). A SAP is a detailed document outlining the procedures for collecting and analyzing samples. The SAPs that were submitted and approved by ECMC’s subject matter experts with this Form 27 are for groundwater monitoring well sampling, water well sampling, environmental sampling (soil and surface waters), and confirmation wipe sampling (structures). In addition to the SAPs, the Form 27 includes a Soil Sampling Locations Plan that ECMC subject matter experts approved. It lays out the strategy for where samples will be collected. Additionally, ECMC included several Conditions of Approval (COAs) to the Form 27. COAs are specific requirements and restrictions placed on projects to ensure compliance with regulations and protect public health, safety, welfare, the environment and wildlife resources. Moving forward, Chevron must use ECMC’s supplemental Form 27s to submit all laboratory results, including sample location maps and analytical summary tables, within seven days upon receipt.

On 5/1/2025 ECMC approved the initial Investigation/Remediation Workplan (Form 27). The Workplan is posted on the spill incident scout card (click docs → search for document #404175397 dated 5/1/2025). ECMC requires operators to submit an Investigation/Remediation Workplan for any spill or release of waste for which cleanups and remediation is anticipated to take longer than 90 days.

In summary, the Workplan describes the ways in which impacts from the incident will be remediated and how the remediation will be monitored and validated. The impacts are described the Analytic of Source Material documentation (view document #2358839, posted 4/25/2025). Additional documentation of impacts and sampling data is also posted in the scout card.

Additionally, ECMC included several Conditions of Approval (COAs) to the Form 27. COAs are specific requirements and restrictions placed on projects to ensure compliance with regulations and protect public health, safety, welfare, the environment and wildlife resources. Moving forward, Chevron must use ECMC’s supplemental Form 27s to submit all laboratory results, including sample location maps and analytical summary tables, within seven days upon receipt.

The Workplan also discloses that as of 4/25/2025, Chevron disposed of 7,194 cubic yards of impacted soils and 89,013 barrels of recovered liquids.

Note: the workplan does not include an Agronomic Sampling and Analysis Plan (ASAP). It is under development and is due to be submitted by Chevron to the ECMC by May 8, 2025.

On 5/31/2025, Chevron submitted a map of parcels within 1.5 miles of the Bishop well blowout. Each parcel has been assigned a unique identification number, and each parcel will be investigated and remediated as necessary to achieve compliance with Table 915-1 across the affected area. There are approximately 300 individual parcels that will be investigated within or around the 1.5 mile radius.

Table 915-1 includes several “classes” of contaminants associated with waste from oil and gas operations: hydrocarbons (organics), metals (inorganics), and soil suitability for reclamation parameters. The table includes parameters for both soil contamination and for groundwater impacts. The table also includes protective standards for residential situations and situations where groundwater may be present or at risk.

In general, operators need to demonstrate that the soil and groundwater present at the site of their operations or where they had a spill or release are cleaned up to meet the standards set forth in Table 915-1. They do this through soil and groundwater sampling to delineate the horizontal and vertical extent of contamination and provide laboratory analysis of the samples they collect.

ECMC staff review the data to determine if the requirements have been met, and may require additional investigation or remediation prior to making that determination. Sites vary in complexity from simple facility closure where only a few samples are necessary to demonstrate compliance to much more challenging settings where soil and groundwater contamination is documented and remediation can take years to achieve clean up. The Bishop incident has the unique complexities of multiple ‘media’ being impacted (soil, groundwater, surface water, and personal property).

On 4/25/2025 ECMC issued a Notice to Operators (NTO) regarding pressure management safety. As a regulatory authority, ECMC uses NTOs to communicate timely and important information to operators and may require certain action be taken as necessary and as part of ECMC’s regulatory program.

This NTO requires operators to conduct an assessment of their processes and wellhead procedures during the time period between drilling rig release and start of production and to report that assessment to ECMC. The goal of the NTO is to ensure proper application of technical, operational, and organizational processes, specifications, and solutions to reduce risk to health, safety, wildlife and the environment during pivotal times in the development of a well. The NTO reflects ECMC’s mission to regulate the development and production of oil and gas in a manner that protects public health, safety, welfare, the environment, and wildlife resources.

ECMC issued the NTO out of an abundance of caution and in light of initial findings from ECMC’s investigation into the Bishop incident, however no final determination of the cause of the incident has yet to be determined. ECMC will continue to investigate, in collaboration with the operator and other regulatory agencies, the cause of this incident. As more specific information becomes available, ECMC will take additional action as necessary to protect public health and safety.

There are 260 operators with active wells in Colorado. Operators that do work pertinent to the NTO – as indicated by having one or more wells listed as ‘Active Permit’ status – were required to respond to the NTO by 5/9/25. Well status data is available on the ECMC dashboard (page 2). As of 5/14/25, ECMC received responses from 38 of 42 operators that have Active Permit status wells to which the NTO is immediately applicable. ECMC staff has reviewed those submittals. In summary:

• 30 submittals are compliant. ECMC staff found demonstration of safety protocol review and effective communication with field staff and contractors. ECMC staff also found that the plans properly integrated operator leadership signatories: ECMC required that the summary was required to be signed by the operator’s leadership, including but not limited to titles such as Executive Vice Presidents, Chief Operating Officers, or Presidents.
• Seven submittals need supplemental information. ECMC staff has requested additional supplementary information to fully substantiate the requirements of the NTO.
• One operator did not demonstrate compliance with the NTO. ECMC has contacted the operator to require a re-submittal.
• ECMC has contacted the four operators who failed to respond by the deadline.

ECMC collects spill and remediation data from operators per our regulations. That data is publicly posted on our COGIS database upon review by ECMC's expert remediation inspectors. Generally, the data is posted within 72 hours of receipt. Chevron is required to document its work through the submittal of various forms, including but not limited to: the Form 19 Spill/Release Report, the Form 27 Site Investigation and Remediation Workplan, the Form 15 Earthen Pit Permit, the Form 22 Accident Report, and the Form 23 Well Control Report. Once an Operator's Initial Spill/Release Report is approved by the ECMC, a unique Facility ID is assigned to track spill response and cleanup records. Spill/Release ID #489797 has been assigned to this incident. The Spill/Release scout card will serve as a repository for supplemental information provided by the Operator on Form 19 Spill/Release Reports.

On 4/24/25 ECMC posted Chevron's ‘Analytical of Source Material’ documentation (view document #2358839). The document includes the test results of oil samples taken on 4/8/25. The samples were taken from two locations near the source of the spill: one sample was taken from the pad of the incident and one from an emergency diversion ditch adjacent to the pad.

In summary, the laboratory analysis identified multiple petroleum hydrocarbon compounds and the presence of certain metals that commonly occur in crude oil. The petroleum hydrocarbon compounds with health based clean up standards are listed in ECMC Table 915-1 and those contaminants of concern drive the remediation approach. You can view Table 915-1 on page 42 of the 900 series. Generally, crude oil is a mixture of multiple organic compounds and sometimes traces of metals. This mixture varies between oil and gas basins and even may be variable between oil wells completed within the same oil and gas basin.

ECMC approved Chevron’s Environmental Sampling and Analysis Plan (ESAP). View the ESAP for the Bishop spill (ID# 489797) via the spill/ release scout card. Click "docs" (above the yellow bar) and download the files dated 4/17/25.

An ESAP is a scientific and technical plan for the collection and chemical analysis of environmental samples for surface water, groundwater, and soil sampling prepared specific to this incident.

The Bishop ESAP plan specifies analytical parameters and methods, timing and frequency of sampling, and applicable quality control provisions. ECMC staff determined that the Bishop ESAP meets the requirements of ECMC’s protective regulations as outlined in the 900 and 600 Series Rules. The ESAP includes a collection of baseline samples to enable us to distinguish between naturally occurring substances and impacts from the incident.

The implementation of the ESAP helps ensure that the soil and groundwater impacted by this incident are properly cleaned up to appropriate regulatory standards. The ESAP will be in effect until compliance is met: ECMC has no timeline estimation at this time.

Specific sample location sites will be determined from field observations and the sampling protocols will follow objectives of the plan. ECMC inspectors also take independent samples to verify the data submitted via the ESAP. The data required in the ESAP supplements the initial testing/data that occurred during the emergency response phase.

Chevron provided the first drafted ESAP to ECMC on 4/10/25. ECMC’s experts approved the plan on 4/17/25 after Chevron provided additional information in the ESAP.

Contact an ECMC liaison at dnr_ecmc_communityliaison@state.co.us if you seek assistance understanding the spill reporting process and associated documents.

NOTE: many of these forms refer to the location as Noble or Noble/Chevron. The previous operator was Noble. The current operator is Chevron.

• The state’s pre-incident permitting/inspection history of the site is publicly available on the ECMC's website via the well scout card.
• As documented on the scout card, this well was initially drilled on 12/23/2023.
• The scout card provides comprehensive well information including approved permitted well construction details. This includes permitted depth of the well, formation and spacing, casing, and cement details.
• ECMC has published a help guide for using scout cards.
• The Bishop #A18-742 well is one of sixteen wells drilled on the A07-01 Pad, ECMC Location ID #483510.
   

All ECMC rules and regulations are available on our website. Operators must comply with these rules and ECMC holds operators accountable to rules. The following rules pertain to spill incidents:

• ECMC’s 900 Series rules apply to the management of Exploration and Production Waste and Environmental Impacts.
• ECMC’s 600 Series rules govern safe operations during oil and gas operations.

• Press statement: Chevron/Bishop well control incident transitions to state regulatory oversight (4/15/2025, 2:00 PM)
• Questions & Answers Regarding the Bishop Well Control Incident in Weld County (4/15/2025)
• Update to Commission about Incident at Public Hearing (4/23/2025)
• Press statement: 483510 Noble/Chevron Bishop A07-01 pad (4/7/2025, 10:00 AM)
• Update to Commission about Incident at Public Hearing (4/9/2025)
• Bishop Well Control Incident Fact Sheet (4/11/2025, 4:00 PM)

ECMC Contacts

Community and Resident Inquiries:

Megan Adamczyk (ECMC Community Relations Liaison)

Yesica Chavez (ECMC EJ Community Liaison)

Email ECMC's Liaisons

Phone:(888) 235-1101

Media Inquiries:
Kristin Kemp (ECMC Public Information Officer)

Email Kristin Kemp

Phone:(720) 666-0437

Other Contacts

Contact the Weld County Office of Emergency Management (OEM) for any matters related to the emergency or residential displacement.

Phone: (970) 400-4264

Web: https://www.weld.gov/Government/Departments/Office-of-Emergency-Management

Contact the Weld County Department of Health and Environment for concerns about health and safety.

Phone: (970) 400-6410

Additionally, the Colorado Department of Public Health and Environment (CDPHE) provides expertise related to potential health impacts from oil and gas operations.

Phone: (303)389-1687

Email:cdphe_oghealth@state.co.us

Contact the Chevron Complaint Hotline to coordinate remediation of your property.

Phone: (877) 359-1285

Email: inquiries@bishopwellincident.com

Chevron Incident Website 

For livestock/ crop concerns, please contact your veterinarian and/ or review the Weld County agriculture-related resources.