Water Storage

Baffle Wall Specialists – At Preload, we have unmatched experience in the design and construction of internal baffle wall configurations to help our clients meet the Safe Drinking Water Act (SDWA) regulations for disinfection. We know how to configure the baffles to direct the water and efficiently achieve the required chlorine contact time (CT).

Why Use Baffle Walls – To kill or inactivate such harmful organisms as Giardia cysts and bacteria, disinfectants are added to water systems. The effectiveness of the disinfectant depends on several factors, an important one being the amount of time the water stays in contact with the disinfectant or “hydraulic residence time.” The addition of properly configured baffle walls to a tank can result in a more efficient “hydraulic residence time.”

Baffle Wall Designs – The most common baffle wall configurations are straight or a combination of c-shaped and straight. Baffle walls may be precast, cast-in-place, masonry block, or fabric.

At Preload, we are well versed in designing and constructing all varieties of baffle wall solutions. As a leading provider of effective water storage solutions since 1930, we are at the forefront of configuring water storage tanks to meet SDWA-mandated CT values. Communities nationwide are turning to Preload for today’s most advanced baffle wall tank designs.

The Preload Team analyzes the topography, geology, and other local conditions when designing and constructing a tank. Our flexible designs can accommodate a wide range of adverse or unusual loading conditions. Prestressed concrete tanks utilize a unique concrete floor system which can accommodate substantial settlement while remaining watertight. We have constructed tanks in all types of soil conditions on all manner of foundations.

We can vary the height-to-diameter ratio and tank elevation to meet your facility’s design, hydraulic gradient, and space requirements. A detailed site layout and construction plan can be developed during the project design phase to assure the most efficient use of property and accommodate future expansion, as required.

Preload tanks can be fully buried, and can even be designed to resist hydrostatic uplift in flood-prone areas. We frequently design and construct tanks in seismic zones and on sites with differential backfill elevations.

Selecting the right accessories to meet operational needs is one of the most crucial decisions made during the design process. We know Operators will be interfacing with Preload tanks for generations which is why we offer near unlimited options for accessories focused on safety, durability and operational efficiency.

Preload knows the safety of your employees is paramount and our tank accessories are designed to comply with the most current OSHA regulations and guidelines. Unless otherwise specified, all Preload tanks are designed with OSHA compliant ingress / egress, fall protection and enclosures around commonly accessed tank features.

Security of a community’s water system is essential to public safety. That’s why Preload offers many features to protect your tank from unauthorized access.

• Preload offers securely fastened, stainless steel security vents protected by heavy-duty cages. We can further protect these vents with two layers of stainless steel screening. For buried tanks, we offer gooseneck vents that utilize two layers of stainless steel screening.
• Preload offers stainless steel screening to guard tank overflow exits. Our screening is heavy-duty and securely fastened. In addition, we can install a duckbill-type check valve up-line of the exit.
• Preventing unauthorized climbing on tank ladders is an especially important security feature that Preload offers. We install anti-climb plates that securely lock the ladder to stop intruders.
• We offer and install dome hatch intruder alarms that notify a central control station in the event of an attempted intrusion.
• May be protected with heavy-duty security covers equipped with padlocks.
• Preload can install intruder detection systems that integrate video and motion detection features located on and around the tank, with wireless connection to a central control station.

Preload tanks can incorporate all variety of mixing systems to address operational and water quality considerations. Mixing is often utilized to prevent tank short-circuiting, dead zones, reduce water age, THM removal (see THM removal) and improve overall water quality. Mixing systems are commonly categorized as either passive and active mixing systems.

Active mixing systems use mechanical equipment inside the tank to drive an vane or propeller which provides mixing. Active mixing systems require a power source and periodic monitoring to verify that they are functioning or in need of repair. Generally, these systems mix the tank relatively slowly; however, they do not impact filling or drawing operations.

Passive mixings systems are built into the internal tank piping and provide mixing through the cyclical filling and emptying of the tank. Passive mixers contain no mechanical equipment, do not require a power source and require very little monitoring or maintenance. However, the valves create some minor head loss into the system and mixing only occurs during filling or drawing. Therefore, little mixing is achieved during periods of low tank usage.

Trihalomethanes (THM’s) and other disinfection by-product have recently become increasingly regulated. Strict monitoring and treatment has been required in systems prone to THM generation.

Preload tanks are highly flexible and uniquely adaptable to nearly all types of THM monitoring and removal systems. THM removal is often achieved utilizing mixing systems in conjunction with surface aeration, agitation and forced draft ventilation. This equipment is easily supported and accommodated by the concrete tank wall and roof.

Interior aerators can be attached to the tank wall with no long-term impact to the durability and serviceability of the tank. The concrete roof is fully capable of supporting the weight of mechanical blower and ventilation equipment.

Further, should an existing tank require a THM removal system retrofit, Preload has substantial experience in the design and installation of these retrofits.