Water Tap Application: Small and Large Service Connections

The City of St. Louis Water Division is the sole agency allowed to make a tap into an existing water main. 

However, it is the responsibility of the customer to correctly size both the service tap and service line. 

Also, it is up to the contractor requesting the tap to do all excavating, to install the piping, valve and meter boxes or meter vaults, and to complete all backfilling and grade restoration.

The contractor is to clearly mark the main at the location of the desired water tap.

1. Determine the type of tap application: Small Service Connection or Large Service connection
2. Correctly size both the service tap and service line using information in the 'Additional Information' section below.
3. Apply and obtain an Excavation Permit from the Street Department
4. Apply and obtain a Plumbing Permit from the Building Division
5. Include the plumbing contractor's name that is referred to on tap applications in the plumbing and excavation permits. 
6. If a backflow prevention device is required, a copy of the purchase order or bill of sale for the backflow prevention device.
7. Copy of an approved drawing stamped and signed by the Fire Marshall's Office (for fire connections) and/or the Plumbing Section of the Building Division (for domestic service connections)
8. Completion of an application for service from the City of St. Louis Water Division Customer Service Section
9. The check or money order made payable to the City of St. Louis Water Division shall be from either the plumbing contractor or the holder of the water service account.

The Water Division will only schedule the installation of the tap after all of the items listed below have been supplied to the Water Division.

Applications For Small Service Connections

Applications for small taps need to be made in person at:

Be sure to bring with you:

1. Check or Money Order made payable to the "The City of St. Louis Water Division" in the amount of the cost estimated for the service tap installation.
2. Copy of the Excavation Permit from the Street Department.
3. Copy of the Plumbing Permit from the Building Division.

Applications For Large Service Connections

Be sure to bring with you:

• Check or Money order payable to the "The City of St. Louis Water Division" in the amount of the cost estimate for the service tap installation.
• Copy of the Excavation Permit from the Street Department.
• Copy of the Plumbing Permit from the Building Division.
• If a backflow prevention device is required, a copy of the purchase order or bill of sale for the backflow prevention device.
• Copy of an approved drawing stamped and signed by the Fire Marshall's Office (for fire connections) and/or the Plumbing Section of the Building Division. (for domestic service connections)
• Completion of an application for service from the City of St. Louis Water Division Customer Service Section.

Various Tap and separate department fees may apply.

Water Service Tap into an existing water main per specifications set by your Plumber and approved by the City of St. Louis Water Dept.

Water Service Connections Categories

Water Service Connections are divided based upon the following categories:

Size

• Small Service Connection: All service lines that are less than six (6) inches in diameter, and where the installed service line is a metal pipe, not cast iron or ductile iron pipe
• Large Service Connection: All service lines that are six (6) inches or larger and any connections designated as a "Cast Iron Connection" by the Water Division

Use

• General Supply (G.S.): Domestic Use only
• General Supply Limited Service Sprinkler (G.S. LSS): Domestic Use and Limited Fire Protection
• Automatic Sprinkler (A.S.): Fire Protection only
• Combined (A.S.- G.S.): Domestic Use and Fire Protection

Number

• Single: One service line for one use
• Dual: Two taps on either side of a line valve, which are then interconnected
• Through: Two or more taps on different water mains, with all of the service lines interconnected inside the property line

Piping

• Single: One service tap supplying one service line crossing the property line
• Split: One large service tap supplying two service lines crossing the property line, A.S. & G.S.

Small Service Connection Specification

A small service connection is any connection with a service tap less than six (6) inches in diameter, and where the installed service line is a metal pipe, not cast iron or ductile iron. Current plumbing codes require a minimum of 1" copper service line.

A small service line cannot be greater than 3" in diameter copper pipe. Small service connections shall only be a single number and single piping as outlined above.

It can only be used for Fire Protection (A.S.), Domestic Use (G.S.) or Domestic Use and Limited Fire Protection (G.S. LSS).

Small service taps shall not be made on a 20" or larger water main unless that main is the smallest water main available, or the tap is approved by the Water Commissioner.

There are four sizes of small taps available:

• 1" service tap is directly tapped into all mains 6" and larger
• 1 1/2" service tap requires a tapping saddle for 6" water mains, is directly tapped into larger mains
• 2" service tap requires a tapping saddle for 6" and 8" water mains, is directly tapped into larger mains
• 3" service tap will consist of two-2" taps, requires a tapping saddle for 6" and 8" water mains, is directly tapped into larger mains

Large Service Connection Specification

A large service connection is any connection with a service tap which is six (6) inches in diameter and larger, and any other connection that was designated as a "Cast Iron Connection" by the Water Division at the time it was installed. These are 3" and 4" connections made with cast iron or ductile iron piping.

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