Custom Fiberglass PAC Enclosure for Maryland Water Treatment Case Study
A Maryland Water Treatment Plant needed an enclosure for a new powdered activated carbon (PAC) storage and feed system. The shelter had to protect the equipment, maintain a dry, low-humidity environment, and meet hazardous electrical requirements.
For this project, Shelter Works worked closely with the project's engineers and Will Hesse at Envirep, a manufacturer's representative that provides high-quality solutions for municipal and industrial water applications to the Mid-Atlantic states.
The plant utilizes a PAC system in its water treatment process. Because PAC is a fine, highly porous material, it is often introduced at multiple points in the treatment process using dedicated feed systems. At this Water Treatment Plant, the PAC is injected before the flocculation tanks, upstream of the gravity plate settlers. To ensure the feed system's safe and reliable operation, the PAC system must be protected from environmental exposure by an enclosure that meets hazardous location electrical requirements.
Why PAC Systems Need Reliable Enclosures
Powder-activated carbon is a cost-effective choice that offers numerous benefits in water treatment, including taste and odor control, as well as the removal of organic compounds. Its fine particle size allows for quick adsorption and is suitable for single-use dosing.
However, carbon dust can also pose operational hazards if not properly contained. Without a well-designed shelter, carbon dust can escape into the surrounding environment, infiltrate sensitive electrical equipment, or create combustible dust conditions. This makes thoughtful enclosure design critical for site safety, regulatory compliance, and equipment longevity.
PAC should also be stored in a cool, dry space between 40°F and 80°F to minimize condensation and humidity, which can lead to clumping and caking that can affect dosing efficiency.
The Shelter Works Solution
To meet the plant's needs, Shelter Works custom-designed and manufactured a 10' x 10' x 10' fiberglass shelter engineered with safety in mind for its use in a hazardous location.
Key features include:
- Insulated Construction – 2-1/2" foam insulation in walls and ceiling in conjunction with a 1-ton air conditioner maintains ideal system operating temperatures and controls humidity levels.
- Structural Reinforcement – Wood reinforcement in all four walls for mounting heavy equipment and enhanced structural stability.
- Hazardous Location Electrical Compliance – NEC-compliant switches, receptacles, lighting, hazardous-location exhaust fan, and 1-ton air conditioner with heat.
- Safe Access - Double doors with a trip-proof threshold for easy movement of supplies and equipment.
Why Fiberglass is the Right Choice for PAC Applications
Shelter Works fiberglass buildings are the ideal solution for PAC storage and feed systems for several reasons:
- Corrosion and Dust Resistance – Unlike steel or wood, fiberglass will not rust, rot, or degrade when exposed to fine carbon dust, moisture, or cleaning chemicals.
- Non-Conductive and Low Maintenance – Unlike steel or wood, fiberglass will not rust, rot, or degrade when exposed to fine carbon dust, moisture, or cleaning chemicals.
- Custom Engineering for Safety Compliance – Shelter Works designs and manufactures enclosures to meet specific hazardous location classifications and local electrical codes.
- Long-Term Durability – With an expected lifespan exceeding 40+ years, Shelter Works fiberglass shelters provide reliable protection without the need for costly structural repairs.
Why Shelter Works : Collaboration and Results
When asked about his experience working with Shelter Works on this project, Envirep's Will Hesse stated, "By working with the project's engineers from the early design phase, we were able to provide an enclosure that met the customer's operational requirements. This shelter ensures the PAC system will operate reliably, keep plant personnel safe, and protect the feed system from weather and environmental exposure."
Custom fiberglass shelters from Shelter Works offer unmatched protection, code compliance, and long-term value. This Maryland Water Treatment Plant project demonstrates how strategic partnerships between manufacturers, representatives, civil engineers, and municipal operators can produce safe, effective, and lasting solutions essential to water treatment infrastructure.