STI Precast

A New England mainstay, STI Precast (Formerly Sani-Tank) has been serving our clients’ precast concrete needs for more than 60 years.

Our Products

Sewer and drain manholes

Precast concrete from STI will last under the toughest conditions

Catch Basins

Sizes to Fit any Need

Septic Tanks and Leaching Basins

The most durable precast septic products 

MagnumStone™ by CORNERSTONE®

Retaining Walls

Get a Quote For Your Project

No Project Too Big Or Too Small

We expertly install the following products:


  • Drain Manholes, Sewer Manholes, Catch Basins (4′-8’ID)
  • H10 Monolithic & Two Piece Tanks
  • H20 Tanks up to 12,000 Gallons
  • Light Pole Bases
  • Leaching Chambers
  • Mangmstone Retaining Wall Systems
  • Hydroworks Water Quality Units
  • Transformer Pads
  • Custom Fabrication

MagnumStone™ by CORNERSTONE®

Retaining Walls


Natural Stone Face

A process that embeds a true natural stone face into our precast concrete retaining wall.

Without Compromise

The natural stone is embed into the concrete. There is no chance of pieces falling off or delminating.

Fully Engineered

The natural stone will not bleach or weather due to sun exposure or weather related problems.

Serving New England for more than 70 years!

Located in North Central Massachusetts, STI Precast (formerly Sani-Tank) has been serving the New England area’s precast concrete needs for decades.  

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Retaining Wall System

MangumStone™ is a large wet-cast retaining wall system, cleverly engineered with a hollow core. Its hollow design uses nearly half the concrete of a solid system while maintaining all of its strength and durability. The environmental and economical advantages of the MagnumStone™ system are unprecedented in the industry.

Green Advantages

MagnumStone uses less concrete than traditional solid wall systems offering more sustainable construction options, contributing less CO2 to the environment during production and delivery process. 

Production Advantages

Its unique hollow core design means less concrete to pour, making the units lighter for handling purposes and reducing the amount of cement required per block.

Transportation Advantages

MagnumStone’s light weight design maximizes each truck load to the site, reducing the number of trucks on the road, and their carbon footprint. Plus, each unit can be loaded and unloaded quickly and easily two at a time, reducing time and labor on the job site.

Installation Advantages

The large light weight hollow core MagnumStone™ units can be installed quickly, to create curves and turn corners, with smaller equipment and less labor. 

Design Advantages

The MagnumStone’s large vertical and horizontal cores allow wall designers the flexibility of creating many solutions without environmentally costly side-effects.

Its unique internal drainage system, and ease of incorporating both through wall, and top of wall details makes it the prime choice for environmentally friendly wall solutions.

Contact Us

60 Lanides Lane, Leominster, MA


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