Tap water can affect grass health. It may contain impurities that damage the soil, discourage growth or even kill the turf. Most tap water is safe to use on lawns, but pH balance and contaminants should be checked to help ensure healthy grass.
High chlorine content in tap water can suffocate turfgrass and make it more susceptible to disease. Also, too much nitrogen can burn grass due to high levels of nitrates – a common pollutant found in wastewater.
Tap water can cause excessive salination if used frequently; this causes wilting and discoloration of grass blades and, eventually, death from dehydration. Also, many municipal water supplies have elevated levels of minerals, including calcium and magnesium carbonates which harm root growth.
Hard tap water also carries an alkaline taste that some people find unpleasant when used for drinking or cooking vegetables or fruit. Test your tap water regularly to determine any issues with acidity/alkalinity that could cause problems for your lawn or landscape plants.
Saltwater intrusion caused by coastal storms will also increase the salinity of groundwaters, making them unsuitable for use on plants or crops – so if you live near a coastline, check the salt content of your tap water before watering!