ALL4 Announces Their First Three Principals
FOR IMMEDIATE RELEASE
ALL4 Announces Their First Three Principals
Philadelphia, PA (August 13, 2026) – ALL4 is proud to announce the appointment of Sharon Sadler, Dan Dix, and Eric Libolt as the company’s first Principals. Principal is a new leadership role within ALL4 created to recognize and empower leaders who have consistently driven client success, technical excellence, and strategic expansion across the organization.
As ALL4 has grown, so have the needs of its clients and the caliber of leadership required to serve them. The Principal role recognizes leaders who go beyond solving complex technical challenges to lead client relationships, shape strategy, develop teams, and deliver outcomes that build lasting partnerships. As Principals, Sharon, Dan, and Eric will have increased opportunities to grow strategic client relationships, represent ALL4 externally, and help shape the company’s direction.
The three were selected following an evaluation across four key areas: Business Development and Market Leadership, Project and Technical Excellence, People and Team Development, and Leadership and Company Contribution.
The appointment of ALL4’s first Principals reflects the company’s continued commitment to creating leadership opportunities for individuals who combine technical excellence with client service, market leadership, team development, and meaningful contributions to the organization. Sharon, Dan, and Eric have each demonstrated those qualities throughout their careers and will help set the standard for the principal role as ALL4 continues to grow.
Meet the ALL4 Principals
Sharon Sadler
Sharon is a founding member of ALL4’s Washington, D.C. office, which she helped open in May 2015 and led as Office Leader for nearly ten years. Drawing on her proximity to Northern Virginia’s “Data Center Alley” and her previous industry experience, Sharon built and now leads ALL4’s Data Center Sector, helping develop the client relationships and level of service that have established ALL4’s presence in this rapidly growing market.
In her over 22 years in environmental consulting Sharon has served in a variety of leadership and client-facing roles, from opening an office and leading a business unit to coordinating technical staff and project managers, to managing projects and client accounts. That breadth of experience gives her a valuable perspective as she helps define what the Principal role means at ALL4.
As Principal, Sharon will focus on scaling ALL4’s Data Center Sector and growing the team behind it while also expanding the company’s presence in the healthcare industry, a market that played an important role in the early years of her career.
Dan Dix
Dan’s career has grown alongside ALL4 itself. He joined the company in January 2003, during its first year of operation, when ALL4 was an eight-person newly formed company. Over the ensuing 23 years he has played an important role in the firm’s evolution into a national consultancy.
Beginning with a focus on dispersion modeling and ambient monitoring, Dan built a national reputation in air quality modeling and permitting, supporting clients across 37 states and industries ranging from power generation and data centers to refineries. His experience defending permits through depositions, cross-examinations, and expert testimony has contributed to ALL4’s reputation for technically rigorous, legally defensible work.
In 2021, Dan established ALL4’s Air Quality Modeling and Monitoring Technical Team, which grew from five to 10 members and increased revenue by two and a half times over five years. As Technical Director and Key Account Manager for a power sector client he has also helped grow that relationship from a modest account into what is projected to become ALL4’s largest client account in 2026, building a cross-disciplinary team along the way.
As Principal, Dan will continue developing strategic relationships across the power generation and data center sectors, represent ALL4 nationally, and help establish an advancement path for the technical leaders who follow him.
Eric Libolt
Eric brings 30 years of environmental, health, and safety experience to the Principal role, with deep expertise in the petroleum sector spanning remediation, air quality, waste, the National Pollutant Discharge Elimination System (NPDES), and Spill Prevention, Control, and Countermeasure (SPCC) compliance, as well as particular depth in Leak Detection and Repair (LDAR) and Benzene Waste Operations National Emission Standards for Hazardous Air Pollutants (NESHAP).
Eric co-founded Whatcom Environmental Services in 1997, growing its petroleum practice into the firm’s largest line of business and helping build the company to 24 employees before its acquisition by ALL4 in 2023. Since joining ALL4, Eric has led the Washington Business Unit, growing labor revenue by 38% and developing new relationships across the refining sector while expanding the firm’s work into adjacent markets including pipelines and terminals.
An active member of the American Fuel & Petrochemical Manufacturers Environmental Committee and the Western States Petroleum Association, Eric is also leading efforts to establish regional refinery roundtables and a training series designed to strengthen technical depth across ALL4. His leadership emphasizes clear communication, humility, authenticity, technical credibility, and quality as the foundation of long-term client relationships.
As Principal, Eric will deepen ALL4’s presence in petroleum and refining while growing the firm’s remediation practice, leveraging his expertise in soil, groundwater, sediment, and soil gas to diversify the business and build the specialist team needed to support that growth.
About ALL4
ALL4 is a leading provider of strategic consulting services, helping organizations navigate complex Environmental, Health, and Safety challenges across a broad range of heavily regulated industries including pulp and paper, food and beverage, consumer products, cement, chemical/pharmaceutical, transportation, waste management, power, oil and gas, and automotive.
Our areas of expertise encompass air quality, chemical reporting and management, digital solutions, sustainability, investigation and remediation, occupational health and safety, waste management, and water quality. With offices and remote experts across the U.S., Canada, Mexico, Spain, Chile, and Brazil, ALL4 brings a robust North American presence and a growing international footprint—positioning us to support clients seamlessly and effectively around the world.
ALL4 operates from key offices in the metropolitan areas of Philadelphia, PA (headquarters); Rancho Cucamonga and San Juan Capistrano, CA; Atlanta, GA; Louisville and Lexington, KY; Raleigh, NC; Houston, TX; Bellingham, WA; Washington, D.C., Boston, MA; and Madrid, Spain. ALL4 has consistently earned recognition as a “Best Place to Work” both regionally and nationally, reflecting its growth in personnel, culture, and environmental impact. Notable honors include:
- Verdantix Green Quadrant for service providers – Innovator Status
- Inc. 5000 Fastest Growing Companies
- ENR Top 200 Environmental Firms
- Zweig Hot Firm – Fastest Growing Firms
- Best Companies Group
For more information, visit www.all4inc.com and connect with ALL4 on LinkedIn.
