When performing sub-surface excavations in the city of New York, it’s always best to know what’s going on underground before you begin. The underground infrastructure of New York City is extremely complex. Luckily for us, the NYC DEP has kept a rather extensive and detailed catalog of records for many major updates and alterations that have been performed over the past century. Two of the most important records that we at Harris Water Main and Sewer use on a daily basis are referred to in the trade as, tap cards and spur maps.
What are Tap Cards ?
Tap Cards are records kept on file with the DEP that deal exclusively with water main infrastructure. Since the tap is the homeowner’s personal connection to the city main this is very important information to have on hand before breaking ground. These records will tell the contractor the location of the water main tap in relation to the homeowner’s building and curb line using the four compass points (North, South, East & West). The records will also give details on the pipe and city main size located below ground level. Thanks to the record keeping we are able to use this info, coupled with modern day electronic tracking devices to accurately pinpoint the precise location where we need to begin digging.
What is a Spur Map ?
Since we now know that tap cards contain information for city water mains, you’d be correct in assuming that spur maps contain vital information regarding the NYC sewer system. Just as the tap is the connection for the water main, a “spur” is the homeowner’s connection to the city sewer. The spur map will tell us the exact distance your house connection is from the nearest city sewer manhole. It also tells us some other very important information such as the depth and size of city sewers, the type of connection that you have (curb connection, riser or standard spur). Since the NYC sewer system has an average depth of roughly 10′ below street level, this is extremely important information to have.
