Small Diameter Main Replacement refers to Pittsburgh Water’s program to replace older, smaller water mains—typically pipes that are 8 inches in diameter or less—with new, modern pipes. Here’s why this matters:

Why Replace Them?
Many of these small mains were installed decades ago and are prone to leaks, breaks, and reduced water pressure. They often serve residential neighborhoods and smaller streets.

Replacements mean improved reliability, fewer water main breaks and emergency repairs, better water quality as new pipes reduce corrosion and sediment buildup, fire protection as larger, modern mains improve water flow for fire hydrants.

How It’s Done:
Crews excavate the old pipe, install a new ductile iron or similar material pipe, and reconnect service lines. This work often involves temporary water shutoffs and street restoration.

Pittsburgh Water maintains thousands of hydrants, valves, and water relay lines across the city to ensure reliable water service and fire protection. These components are critical for controlling water flow and pressure in the distribution system. Here’s how the replacement process works:

Hydrant Replacement

Hydrants are essential for firefighting and flushing water mains. Over time, they can corrode or fail. To replace hydrants, crews excavate around the hydrant, disconnect it from the water main, and install a new hydrant that meets modern standards. The area is then backfilled and restored.

Valve Replacement

Valves control water flow and allow sections of the system to be isolated for maintenance. Old valves can leak or fail to close properly.

To fix these issues, crews locate the valve, shut down the section of pipe, remove the old valve, and install a new one. This often requires temporary water shutoffs for nearby customers.

Water Relay Replacement

A water relay is a smaller pipe that connects the main water line to hydrants or other system components.

If the relay is damaged or too small for current standards, crews dig up the old pipe and replace it with a new ductile iron or similar material pipe to ensure proper flow and pressure.

Restoration

After replacements, crews backfill the excavation, restore pavement or sidewalks, and test the new hydrant or valve to ensure it works properly.

These upgrades improve system reliability, reduce leaks, and ensure hydrants are ready for emergency use. They’re part of Pittsburgh Water’s ongoing investment in modernizing infrastructure for safety and efficiency.

Urgent sewer repair projects are emergency construction jobs that Pittsburgh Water undertakes when a sewer issue poses an immediate risk to public health, safety, or property. These projects are different from planned capital improvements because they require rapid response and quick mobilization to prevent serious problems.

Examples of Urgent Sewer Repair Projects

Collapsed Sewer Lines – When a pipe failure causes sinkholes, street damage, or backups into homes.

Major Blockages – Severe clogs that threaten flooding or sewage overflows.

Broken Manholes or Catch Basins – Damaged structures that create hazards or allow stormwater infiltration.

Environmental Emergencies – Sewage discharges that could contaminate rivers or streams.

Safety Hazards – Exposed infrastructure or unstable ground conditions that endanger pedestrians or vehicles.