Rainleader Disconnections for Commercial or Multi-Unit Residential Buildings
Usual sources of prohibited discharges
- Roof drains
- Area drains
- Standpipes
- Driveway & dock drains
- Parking ramp drainage
- Foundation drains
Commercial Rainleader Disconnection Permit Required
Although there is no fee, a Commercial Rainleader Disconnection Permit is required before disconnection work can begin. If disconnection work is not completed within the permit timeline, or if the application is not received by the due date, the Rainleader Disconnect Program may issue administrative citations and fines.
Inspection Required
The disconnection must be approved by the Rainleader Disconnect Program. Be sure to schedule an inspection with the Rainleader Disconnect Program after disconnection work is completed, but before it is concealed.
Primary Ways to Divert Rainwater
See illustrations of common commercial connection methods
There are two primary ways to divert rainwater out of the sanitary sewer:
- Reroute rainleaders through the building wall to discharge onto grade
- Reroute rainleaders to connect to a storm drain in the street
Some buildings have flat pitched roofs where rain or snowmelt flows to one end and drains through a downspout or a drainage scupper. The downspout can discharge to the ground or connect to the sanitary sewer through a standpipe. If the downspout is connected to a standpipe, the downspout can be redirected to discharge to the ground, with the standpipe plugged or capped. Water from roofs is not allowed to flow on to a public sidewalk.
Cost Estimates
Below are estimated costs for disconnection of typical roof drains for multi-unit residential and commercial buildings.
These estimates do not include permit costs. Multi-unit and commercial buildings may require additional permits depending on the work required.
Disconnection of Typical Roof Drain in Multi-Unit Building
4" Piping
Includes Material & Installation | Cost |
30' of 4" cast iron pipe Includes cast iron piping, drilling a hole through wood or masonry walls, labor and material costs. | $1,780 |
Core-drilling a hole through solid concrete or block (if necessary) | $942 |
Optional bronze downspout nozzle with galvanized nipple | $355 |
Optional concrete splashblock | $70 |
Total cast-iron cost (approximate) | $3,147 |
Piped using 4" PVC | Less 30% for time & material = $2,203 |
6" Piping
Includes Material & Installation | Cost |
30' of 6" cast iron pipe Includes cast iron piping, drilling a hole through wood or masonry walls, labor and material costs. | $2,508 |
Core-drilling a hole through solid concrete or block (if necessary) | $1,062 |
Optional bronze downspout nozzle with galvanized nipple | $686 |
Optional concrete splashblock | $80 |
Total cast-iron cost (approximate) | $4,336 |
Piped using 6" PVC | Less 30% for time and materials = $3,035 |
Commercial Disconnection from Building to Storm Drain in Street
Contact an outside sewer and water contractor to evaluate the site and design a plan for disconnecting from the sanitary sewer and connecting to the storm drain in the street.
Installation charge will vary depending on work site conditions: depth of excavation, utilities present, storm drain access, storm drain main location in relation to building, traffic concerns, soil conditions, etc.
Above Ground Discharge, Disconnection Inside Commercial Building
Material | Cost |
3" cast iron piping | $45.84/ft |
4" cast iron piping | $53.64/ft |
6" cast iron piping | $75.90/ft |
Last updated Feb 21, 2019
