What Citadel EHS does

Citadel EHS (legal name Citadel Environmental Services, Inc.) is a California-based, employee-owned environmental, health, safety, and sustainability (EHS&S) consulting firm founded in 1993 by Loren Witkin and headquartered in Glendale, CA. The firm delivers nine integrated service lines — engineering and environmental sciences (Phase I/II site assessments, remediation), industrial hygiene, building sciences and hazardous materials management (asbestos, lead, PCBs), environmental compliance and permitting (SWPPP, NPDES, CUPA), air quality, safety, moisture intrusion and microbial consulting, ESG & sustainability, and green building standards (WELL, BREEAM, LEED) — to clients across real estate, construction, healthcare, education, government, industrial/manufacturing, retail, hospitality, and sports/entertainment sectors. Service delivery relies on a multidisciplinary in-house staff of architects, engineers, industrial hygienists, geologists, safety specialists, and environmental scientists using diagnostic equipment such as thermographic imaging cameras, moisture meters, borescopes, Dust Trak aerosol monitors, and Netronix dataloggers, supported by credentials including FEMA Quakesmart (first environmental consultant certified nationally) and LEED Platinum for its own headquarters.

The firm's revenue model is professional services-based: project fees, retainer arrangements, and hourly consulting engagements with public- and private-sector clients, distributed through direct enterprise sales and an industry referral network rather than any self-serve or channel-based motion. Citadel has grown from a single California practice to 11 offices spanning California, the Pacific Northwest (Seattle, Portland), and Charlotte, NC, with notable enterprise relationships including Target Corporation (since 1994), UCLA, Macy's, Caltrans, Turner Construction, U.S. Department of Veterans Affairs, and major refineries. Since 2003 the firm has operated as an ESOP with nearly 50% employee equity participation, and in January 2026 received a strategic investment from St. Louis-based private equity firm Broadview Group to accelerate a buy-and-build growth strategy, evidenced by the 2022 acquisition of RMD Environmental Solutions and the 2026 acquisition of Aurora Industrial Hygiene.

Name

Citadel EHS

Legal name

Citadel Environmental Services, Inc.

Website

https://citadelehs.com

Company type

Private

Founded year

1993

Operating status

Operating

Headcount range

51–100 employees

Short description

Citadel EHS is a California-based, employee-owned environmental, health, safety, and sustainability consulting firm founded in 1993, serving enterprise and public-sector clients across real estate, construction, healthcare, government, and industrial sectors with nine integrated EHS&S service lines from 11 offices.

Ownership category

akta.pro rank

Product category

Environmental, Health, Safety, and Sustainability (EHS&S) Consulting

NAICS

Environmental Consulting Services (54162), Engineering Services (541330)

SIC

Services-Management Consulting Services (8742), Services-Engineering Services (8711)

akta.pro primary industry

Site Assessment & Remediation (Phase I/II, Cleanup Oversight) (BPAHAJAC)

akta.pro secondary industries

Environmental Compliance & Permitting (BPAHAJAA), Air Quality & Emissions Management (BPAHAJAI), EHS Auditing, Inspections & Assurance (BPAHAJAG)

Keywords

• Environmental consulting services
• Industrial hygiene consulting
• Building sciences services
• ESG sustainability advisory
• Hazardous materials management

Headquarters

HQ city

Glendale

HQ country

United States

HQ region

North America

Offices11 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Marketing or Sales, Technology or R&D, Infrastructure

Revenue model

1. Environmental, Health, Safety & Sustainability Consulting Services: Professional consulting services billed on a project/fee basis. Citadel provides technical consulting across environmental site assessments, remediation design, industrial hygiene, safety consulting, building sciences, air quality, moisture intrusion, ESG & sustainability, and green building certification. Revenue is generated through project fees, retainer arrangements, and hourly consulting engagements for public and private sector clients. The firm has a national clientele and international multilingual staff for abroad engagements.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels6 records

Core offering

Citadel EHS is an environmental, health, safety, and sustainability (EHS&S) professional services firm delivering integrated consulting through nine practice areas: engineering and environmental sciences (Phase I/II assessments, remediation), industrial hygiene, building sciences and hazardous materials management, environmental compliance and permitting, air quality, safety, moisture intrusion and microbial consulting, ESG and sustainability, and green building standards (WELL, BREEAM, LEED). Engagements are delivered as project-, retainer-, or hourly-based consulting for enterprise clients across real estate, construction, healthcare, education, government, industrial, retail, and hospitality sectors.

Product overview

Citadel EHS is a multidisciplinary environmental, health, safety, and sustainability (EHS&S) consulting firm offering integrated service delivery. The company provides nine core consulting service areas: Engineering and Environmental Sciences (Phase I/II assessments, remediation design), Industrial Hygiene (exposure monitoring, IAQ), Building Sciences and Hazardous Materials Management (asbestos, lead, PCBs), Environmental Compliance and Permitting (SWPPP, NPDES, CUPA), Air Quality (emissions reporting, permitting), Safety (OSHA compliance, risk reduction), Moisture Intrusion and Microbial Consulting, ESG & Sustainability (carbon accounting, climate risk), and Green Building Standards (WELL, BREEAM, LEED certification). These services are delivered by multidisciplinary teams working seamlessly together across various industries including real estate, healthcare, education, government, and manufacturing.

Differentiator

Problem solved

Functional benefit

Products and services

• Engineering and Environmental Sciences Environmental site assessments (Phase I/II), soil-vapor and groundwater investigations, remediation design and implementation, risk assessments, and regulatory negotiation services from due diligence through closure, delivered to real estate, industrial, and institutional clients.
• Industrial Hygiene Hazard identification, exposure monitoring, indoor air quality assessments, ventilation assessments, PPE determinations, Legionella evaluations, and radiation surveys to protect worker health across industrial, education, healthcare, and refinery environments.
• Building Sciences and Hazardous Materials Management Comprehensive surveys, abatement oversight, and clearance for asbestos, lead-based paint, PCBs, mercury, and other hazardous materials to support safe renovations, demolitions, and re-occupancy, primarily serving real estate, construction, education, and government clients.
• Environmental Compliance and Permitting SWPPP, air district rules, NPDES, SPCC, and CUPA compliance support, audits, and training to keep projects permitted and compliant for industrial, construction, refinery, and government clients.
• Air Quality Emissions reporting, air permitting, and consulting for regulatory compliance with AQMDs including SCAQMD, SDAPCD, and BAAQMD, serving construction, industrial, and refinery clients.
• Safety OSHA compliance gap assessments, injury prevention, construction safety support, process hazard analysis, ergonomics, and safety program development designed to drive organizational success and risk reduction.
• Moisture Intrusion and Microbial Consulting Moisture and microbial investigations, infrared thermographic imaging, remediation oversight, and building forensics to prevent mold and water damage in commercial and residential real estate.
• ESG & Sustainability ESG strategy and reporting, carbon accounting, TCFD-aligned climate risk assessments, GRESB reporting, GHG inventories, and sustainability metrics to support decision-making by corporate, institutional, and real estate clients.
• Green Building Standards WELL Building Standard performance verification, BREEAM In-Use assessments, LEED consulting, Fitwel testing, and indoor environmental quality assessments for green building certification compliance.

Quantifiable outcome

• Established since 1993 with over 30 years of continuous operation and client relationships spanning decades (e.g., Target Corporation since 1994)
• +3 more outcomes

Named customers34 records

Segments9 records

Ideal customer profiles6 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

Two partnerships are on record, tiered core.

• Aurora Industrial HygienecoreStrategic or Co-development Partner · 29 May 2026Acquired by Citadel EHS on May 29, 2026. Aurora Industrial Hygiene was a California-based industrial hygiene and occupational safety consulting firm founded in 1996 by Certified Industrial Hygienists Karen Shockley and Grace Rinck, with offices in San Diego and Los Angeles. The acquisition strengthens Citadel's technical expertise in industrial hygiene, occupational health, OSHA compliance, hazardous materials consulting, and expands its regional footprint across California.
• RMD Environmental SolutionscoreStrategic or Co-development Partner · 30 December 2022Acquired by Citadel EHS on December 30, 2022. RMD Environmental Solutions was a Bay Area environmental consulting firm specializing in subsurface remediation projects. The acquisition enhances Citadel's capabilities in site remediation, regulatory management, and geographic coverage in Northern California. RMD's leadership joined Citadel's engineering and environmental sciences practice.

Scale indicators5 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• Terracon Consultants: Terracon is one of the largest US employee-owned environmental, geotechnical, and materials consulting firms, offering site assessment, remediation, industrial hygiene, and building sciences services closely overlapping Citadel's core practice areas across real estate, AEC, and industrial end markets.
• Haley & Aldrich: Haley & Aldrich is a US environmental and geotechnical engineering consulting firm delivering site investigation, remediation design, building sciences, and EHS compliance services to real estate, healthcare, education, and industrial clients — directly comparable in service mix and client profile to Citadel.
• Roux Associates: Roux Associates is a US environmental consulting firm specializing in site investigation, remediation, and regulatory closure, serving real estate developers, financial institutions, and industrial clients — closely matching Citadel's Engineering and Environmental Sciences practice and target customers.
• Kleinfelder: Kleinfelder is an engineering, environmental, and construction services consulting firm with a comparable multidisciplinary delivery model spanning site assessment, remediation, industrial hygiene, and EHS compliance across infrastructure, water, and real estate sectors.
• Antea Group: Antea Group is a global EHS and sustainability consulting firm providing environmental compliance, site assessment, industrial hygiene, ESG advisory, and remediation services to industrial, real estate, and government clients — comparable in service breadth to Citadel's nine practice areas.
• Trinity Consultants: Trinity Consultants is an EHS consulting firm focused on air quality, permitting, regulatory compliance, and safety services for industrial and commercial clients — directly overlapping Citadel's Air Quality, Environmental Compliance & Permitting, and Safety practices.
• SCS Engineers: SCS Engineers is an environmental engineering and consulting firm specializing in solid waste, air quality, site remediation, and EHS compliance for municipalities and private developers — comparable to Citadel in environmental engineering depth and public/private sector client mix.

Broad incumbents

• Tetra Tech: Tetra Tech is a global environmental, engineering, and consulting services firm offering a far broader portfolio including water, energy, and international development — overlapping Citadel's EHS practices as part of a much larger full-service platform that competes on mega-project scale.
• AECOM: AECOM is a global infrastructure consulting firm with a substantial environment practice covering site assessment, remediation, ESG, and compliance — a much larger incumbent that competes with Citadel on large real estate, transportation, and government engagements.
• Environmental Resources Management (ERM): ERM is the world's largest pure-play sustainability and environmental consulting firm, offering site investigation, EHS compliance, ESG advisory, and climate services globally — competing with Citadel for enterprise and Fortune 500 ESG and remediation mandates at significantly greater scale.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks7 records

Key highlights7 records

Customer concentration

• Xx.com/CitadelEnv
• Facebookfacebook.com/citadelenv
• LinkedInlinkedin.com/company/citadel-environmental-services-inc.

Compliance4 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles13 records

Subsidiaries2 records

Funding overview

Funding rounds1 record

Investors1 record

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A2 records

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Citadel EHS