Garden Hose Dangers and Recommendations
© 2009 Brad Lancaster, www.HarvestingRainwater.com
Many garden hoses leach lead and other chemicals into the water as it sits in the hose. Polyvinyl chloride (PVC) and brass fittings are often the culprits.
To reduce such risk, purchase, use, and/or drink only from hoses labeled safe for drinking water. Never buy any hose with such labeling as “WARNING: This product contains a chemical in the State of California to cause cancer and birth defects or other reproductive harm.” Note that such warnings will typically be in very small print.
A May 2003 Consumer Reports article, “Dare you drink from a garden hose?” reports that hoses labeled safe for drinking leach minuscule concentrations of lead into water standing in the hose, while hoses not labeled drinking water safe leached up to 10 to 100 times allowable lead levels into water standing in the hose.
So, flush any hose before you drink from it by letting the water run a while before you gulp.
Suppliers of hoses labeled safe for drinking water include:
• Flexzilla 3/4-inch interior diameter drinking water safe garden hose
Available in 50-foot, 75-foot, and 100-foot lengths. For 25-foot length hose I buy the 50? hose then cut it in half and insert either a 3/4-inch metal threaded female clinch hose mender clamp (if connected to a low-pressure gravity-fed water cistern/tank), or a 3/4 inch hose barb x 3/4 inch FHT brass threaded female hose repair (which works for both high- and low-water pressure systems). I then have two 25-foot long hoses.
• Gatorhyde Drinking Water Safe Garden Hose: Available in 3/4-inch diameter, but upon inspection I found that it constricts down to 5/8th-inch interior diameter.
For a list of NSF-51 certified hoses, click here.
Note that these are far better than most, but not perfect. Gatorhyde contains polyurethane, while other hoses often contain a less toxic PVC. Both polyurethane and PVC are banned materials in the Living Building Challenge Materials Red List (Prerequisite Five). The Living Building Challenge is an integrated green building guide that goes well beyond LEED.
Note for anyone using gravity to move water through a hose from a rainbarrel or rainwater tank – get 3/4-inch or 19-mm (best) or 5/8-inch or 15-mm (next best) interior diameter hose instead of 1/2-inch or 12-mm interior diameter. The larger the interior diameter, the less surface friction will reduce your low gravity-fed pressure.
Though note that the couplings at either end of the hose will always have an interior diameter smaller than the hose.
For example, a 3/4-inch interior diameter hose will have couplings at either end having a 5/8-inch interior diameter;
while a 5/8-inch interior diameter hose will have couplings at either end having a 7/16-inch interior diameter.
You’ll find the 3/4-inch diameter hose has a much better flow rate than the 5/8-inch diameter hose, and far better than a 1/2-diameter hose.
Avoid “expandable” hoses as their interior diameter shrinks, and needs more water pressure to expand.
And if running pipe from the rainbarrel or tank to the faucet/valve, I use 1-inch (25-mm) interior diameter pipe, rather than smaller-diameter pipe, to reduce surface friction that would reduce gravity-fed water flow out of the pipe and faucet.
Also make sure your rain barrel or cistern faucet/valve does not unnecessarily constrict its interior diameter, resulting in dramatically reduced flow with gravity-fed distribution. To ensure you have the right kind of faucet/valve, make sure it is a full port faucet/valve.