Wastewater Storage Tanks


With over 68 years of experience, CROM understands the complex needs and requirements of wastewater treatment. CROM designs and constructs solutions for all physical infrastructure needs in the wastewater industry.  Prestressed tanks in wastewater treatment plants include equalization tanks, sludge digesters, process water tanks, effluent storage tanks, clarifiers, aeration tanks, sequencing batch reactor (SBR) tanks, bilge storage tanks, and package treatment tanks. 


Prestressed Concrete EQ tanks are a preferred, cost effective solution to contain large volumes of wastewater for Flow Equalization or Wet Weather Storage. EQ tanks are frequently designed to accommodate peak flow conditions and provide steady inflow to the treatment plant preventing combined sewer overflow (CSO) and sanitary sewer overflow (SSO) events.


Prestressed concrete tanks can be used for reclaimed or reuse wastewater. These tanks may be located at the treatment plant facility, or on golf courses and agricultural lands where the treated water is used for irrigation purposes. In Florida, recycling water on site or nearby, reduces energy needed to move water long distances or lift it from the aquifer. This water can also be used as make-up water for chillers in high-cooling environments such as data centers. These are cost effective solutions to the water treatment process.


CROM prestressed concrete tanks can be designed to accommodate various types of clarifier mechanisms. Operating on the principle of gravity settling, clarifiers have been used to treat wastewater for decades and provide efficient solutions to process and purify wastewater.


CROM is experienced in the design and construction of digesters in many configurations and sizes, including open-top aerobic digesters and pressurized anaerobic digesters. Prestressed concrete tanks can be designed to accommodate the requirements and demands of sludge digestion and storage. Prestressing wires can be placed to accommodate multiple wall pipe penetrations. Anaerobic digesters may be built with free-span prestressed concrete domes or designed to accommodate fixed or floating steel covers, aluminum domes, or membrane covers. Mesophilic (90 degrees Fahrenheit) and thermophilic (140 degrees Fahrenheit) processes are possible by applying insulation to the exterior of the tanks. CROM has also designed and built several unconventional structures.


A small diameter, high sidewall, steepy sloped floors, and cone-shaped domes are challenges met by CROM Modified Egg-shaped Digesters.  This type of digester minimizes dead zones at the floor/wall and roof/wall intersections, reducing sludge build-up and the resulting down-time for cleaning and maintenance. The construction of these digesters has proven to be much more economical than traditional egg-shaped digesters.


Oxidation ditch treatment systems typically consist of single or multi-channel configurations with ring, oval, or horseshoe-shaped basins. The structures are designed and constructed in accordance with the applicable portions of AWWA Standard D110 using the Type II wall configuration – shotcrete with an embedded steel diaphragm. As a result, these tanks are known for their outstanding concrete crack control, watertightness, appearance, longevity and minimal maintenance requirements.

Sequencing Batch ReactorS (SBR)

Sequencing Batch Reactor tanks and Biological Nutrient Removal (BNR) tanks are similar from a tank design standpoint.  The AWWA D110 type II walls are modified and reinforced as necessary to provide mounting points for the specialized equipment.

secondary containment

The Unites States Environmental Protection Agency (EPA) has established governing rules to prevent harmful discharges into navigable waters of the US and adjoining shorelines. Secondary containment has proven to provide an essential line of defense in the case of primary containment failure. 

SBRs: Wastewater Treatment Facility Expansion

Fire/Process Water and Wastewater Storage Tanks

Water Reclamation Facility Expansion