Digging Test Pits

Balatazar Construction requested access to the three beaches last week so they could dig some “test pits” along the roads running closest to and parallel to Long Island Sound. Digging these test pits enables them to assess the soil mechanics and the amount of water that they can expect to encounter across the path of the lowest area of the gravity fed sewer system. This information helps them design the pump strategies for “dewatering” sites in active construction areas. This process is essential to maintain a dry, stable worksite, prevent collapses, and ensure safety. Common methods include sump pumping, wellpoint systems, deep wells, eductor wells, and bypass techniques, selected based on soil type, water table depth, trench depth, and flow rates.

Standard Industry Pumping Practices

Sump Pumping: This is the simplest and often cheapest method for shallow trenches with low to moderate water inflow. Contractors dig a sump (a pit or low point) at the trench base or side to collect seeping groundwater or surface runoff. A submersible or trash pump (e.g., 2-4 inch models with automatic floats) is placed in the sump to remove the water, discharging it to a safe location.

Pros: Low cost and easy setup.
Cons: Water enters the trench first, potentially causing instability; not suited for high-flow or deep sites.

Wellpoint Dewatering: For trenches in permeable soils like sand or gravel where proactive groundwater control is needed, contractors install a series of small-diameter (1.5-2 inch) wells (wellpoints) along the trench perimeter, spaced 3-6 feet apart. These are jetted or drilled in, connected to a header pipe, and linked to a vacuum-assisted centrifugal pump that lowers the water table before excavation starts (typically effective up to 15-20 feet deep). Water is drawn into the wellpoints and pumped out. This method is common for sewer and water line projects to create a dry, stable zone.

Pros: Prevents water entry, enhances safety, and reduces delays.
Cons: Higher initial setup cost due to drilling and specialized pumps; may require multi-stage setups for deeper trenches.

Eductor (or Jet) Wells: Suitable for low-permeability soils like silts or clays in deeper trenches. Small wells with eductor nozzles create a vacuum to draw water up through piping to an at-grade pump station.

Pros: Low maintenance and no suction depth limits.
Cons: Limited to lower volumes; requires close spacing.

Attendees

Although all three beaches were invited to meet with the crew from Baltazar, no Miami Beach or Old Colony Beach representatives were in attendance. The list of attendees who met with the contractor on the morning of Tuesday February 17, 2026 was:

• • John Cunningham, OLSBA President
  • Paul Yellen, OLSBA Vice President (former OLSBA President)
  • Jack Reynolds, OLSBA WPCA
  • Roger Zito, OLSBA WPCA
  • Bill Reynolds, Old Lyme Resident

Paul and I arrived together first and introduced ourselves to the Baltazar crew, composed of the four project managers expected to be overseeing the various construction projects. We spent about an hour standing in the cold around a tailgate reviewing drawings and answering one another’s questions. The crew made a positive impression as no-nonsense individuals with a solid foundation. We look forward to learning the results of their test pit efforts.

John Cunningham
OLSBA President
February 20, 2026