Over the years various different materials have been used to install water service lines, also referred to as water mains even though that is technically incorrect. What follows is a brief tutorial about the different plumbing materials that have used for water supply lines into private properties over the years and their particular characteristics.
Lead – Lead Water Service Lines
Lead has not been an approved material for a water main service in over 60 years. Lead in the drinking supply does not occur naturally; it does not come from rivers, reservoirs, etc. If lead is present in a house supply system it typically emanates from the water main distribution system or house plumbing.
There are various services that test for lead inexpensively. If a house is serviced by a lead water main it is strongly suggested that before using water the tap be run for 15 to 30 seconds when it has not been run for 6 hours or so. This precaution will help eliminate the possibility of ingesting lead which could lead to lead poisoning.
There are a few ways to determine if a water main service line is lead. Lead is characterized by a silver color, is malleable, and has a round shaped “wipe joint” just before the main control valve (refer to photo and video). Wiped joints had to be used because lead cannot be threaded like a pipe can.
The NYC DEP code does not permit the repair of an existing lead water service line. If repair work is needed on a lead service line by law it must be replaced. In addition once an existing lead water service is moved in any manner tiny hairline cracks are made, which will form into a leak typically within 18 months or less.
Galvanized – Galvanized Water Service Lines
Galvanized pipe that was used for water main service lines are primarily found in areas where NYC residents were previously serviced by a private water supply company such as Jamaica Water (JWP). Galvanized pipe is not legal in NYC as a material for a water service.
Galvanized piping reacts to contact with water or moisture, and corrodes on both the outside and inside of the piping (refer to photo and video). It is similar to a clogged artery in a person – Only instead of a heart attack you get a flood! It is strongly suggested that any existing galvanized water service be replaced immediately with better materials, as when they leak the service typically ruptures.
The NYC plumbing code does not permit repairs on existing galvanized water main service lines. In addition repairing an existing galvanized water service would be a repair with little integrity. The same applies for an existing lead water service line.
Typically when water is turned on in a house with galvanized piping the initial water will be rust colored or contain rust. Impurities in levels such as these are not typically found in copper water services
Copper – K Copper Water Main Service Lines
K type copper is the material that the vast majority of water services are installed with in NYC by a licensed master plumber. In addition most existing water services are K copper. K copper tubing (not pipe) is used for water services up to 2″ in size.
K copper water services are characterized by flare fittings at the end of the tubing (refer to photos below) and the fact that they are malleable and able to bend without damaging the service line. This is a key factor in why they last so long as they are able to withstand ground shifting better than other approved plumbing materials. K copper water services typically have a lifespan in excess of 50 years. [Read more about copper water main lines]
Brass – Brass Water Main Service Lines
Brass pipe is threaded at each and is connected by the use of brass couplings. Brass is generally used solely for a 2 1/2″ water service line in New York City. Therefore it is a material that is used infrequently, and it is expensive compared to other approved water supply line materials.
Brass is a metal composed primarily of copper and zinc. Copper is the main component and brass is usually classified as a copper alloy material. Brass is stronger and harder than copper, but not as strong or as hard as steel. Brass water services have a life expectancy in excess of 50 years.
Brass is not a magnetic material; so to test whether a water service is galvanized or brass a magnet can be used. Galvanized is a magnetic material. Brass and galvanized pipe can appear similar to the naked eye, but have very different characteristics and properties. Both brass and galvanized are threaded pipe, however unlike galvanized pipe brass is a legal material in NYC and has a much longer life expectancy.
Ductile Iron Pipe – Ductile Iron Water Main Lines
Ductile Iron pipe is a cement lined material used for water services larger than 2″ in diameter. Typically used for fire sprinkler mains or for large buildings such as apartment buildings.
Ductile Iron pipe is the same material that NYC uses for its distribution system and lasts for many decades. Our of all the materials used, Ductile iron may be the most durable water service material approved for use in NYC.
Ductile iron pipe is put together with either push-on joints or mechanical joint retainer glands with set screws. Ductile Iron Mechanical Joint pipe contains no lead whatsoever (refer to photos). In some specific instances, such as unstable ground conditions, ductile iron pipe is used for house sewer installations as well as for a water main.