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Drinking Water and TDS

When you drink from your tap, refrigerator, or bottled water do you think about TDS in your cup? Water standards are in place that enable our cities to keep our drinking water safe and within the correct limits. However, it is often interesting to do your own test just to see what the results are.

Defining terms:

Dissolved solids refer to any minerals, salts, metals, cations or anions dissolved in water. Total dissolved solids (TDS) typically comprise inorganic salts (principally calcium, magnesium, potassium, sodium, bicarbonates, chlorides, and sulfates) and some small amounts of organic matter that are dissolved in water.

The current EPA TDS standards & info (taken from http://www.tdsmeter.com/education?id=0018): In terms of Total Dissolved Solids (TDS), in the U.S., the Environmental Protection Agency (EPA) advises against consuming water containing more than 500mg/liter, otherwise known as 500 parts per million (ppm) of TDS, although many health specialists believe that ideal drinking water should be under 50 ppm or lower. The average tap water in America contains approximately 350 ppm of TDS although it is not uncommon for municipal or local water supplies to exceed this. If TDS levels exceed 1000mg/L, however, it is generally considered harmful to human health and should not be consumed.

We recently were told by a customer that they performed a TDS test on their water. We had installed 2 rainwater systems on their property. This property has a small herd of cattle and while we were installing there was dust settling all over our tools and equipment that the animals stirred up daily. The guttering has normal screen and both systems have first flush diverters on them. The customer told us that they tested bottled water at 3 TDS. One of their systems had 1.3 TDS and the other had 1.8 TDS. They were amazed at the results that the rainwater they collected has less Total Dissolved Solids than the bottled water.

By no means are we saying this water is drinkable straight out of the cistern. We are purely recounting what the customer told us. We have seen this test performed on other types of water as well with very similar results. With proper treatment the water from the cistern will be safe to drink. It also requires less treatment in many cases than well water.

We encourage educating yourself on the subject of Total Dissolved Solids in drinking water. There are multiple resources out there discussing the subject in depth. There are many inexpensive options out there as well allowing you to test your own water in the privacy of your own home if you are curious enough to do so. Your city’s municipal water supply is supposed to supply you with information about their annual results of the drinking supply. This is often on their website or sent to their customers. We are lucky to live in a country that enables us access to clean, safe drinking water.