Total Dissolved Solids – An Overview
Natural Total Dissolved Solids
Through natural ancient upheavals that created the Rocky Mountains to the Grand Canyon, rocks and soil deposits occurred. In these deposits lie minerals and elements that, in part, make up what we call planet earth and contain the many attributes of Total Dissolved Solids (TDS). Some areas will contain a higher concentration of these minerals and elements, while other areas will contain lower concentrations.
Water is the universal solvent, so think about our streams, rivers, lakes, underground aquifers. Through time, the minerals and elements will dissolve because of this universal solvent we call water. Through this natural process, the dissolved minerals and elements will inevitably, make their way into our drinking water supplies. The minerals and elements that can be in our water supplies include Calcium, Phosphorus, Sodium, Potassium, Iron and Zinc.
In general terms, the minerals and elements that make up TDS, are salts and metals. Some are essential building blocks to life and help maintain the health of our bodies, and the health of our pets. They are also an essential part needed for the growth of our food supplies, from home gardening and farming, to raising cattle and poultry. TDS is everywhere, just look around the next time you are taking a walk or a hike, and pause to enjoy that sip of water.
Food and Drinks
What we eat and drink contains elements that contribute to Total Dissolved Solids (TDS) and make their way back into the natural cycle of things. Now, while this may not be the best subject to discuss at parties or dinners out, human waste is part of our life cycle and a reality. Drinking water already contains minerals and elements, TDS, as mentioned in the natural source article. Water is also a part of other beverages that we enjoy, like coffee, tea and sodas. What our bodies do not utilize for bones, tissue and vital organs the body then expels.
The foods that we eat can contain TDS as preservatives, nutritional values (Recommended Daily Allowances) and so forth. The body also expels what is not utilized from these foods, and where do these un-utilized sources go? You guessed it, every time you flush the toilet; it travels down the sewer lines and to the Water Reclamation Facility, (a.k.a. wastewater treatment facility). Now at this point the TDS we return plays into the perpetual natural cycle.
Processed foods contain salts (TDS), preservatives, coloring additives and other items, that some of us cannot even pronounce, used for extending shelf life and a pleasant color appeal. One health concern, across the nation, is the intake of sodium (salt), a part of TDS, and the effect on raising one’s blood pressure. Healthy eating lends itself to a more natural food source and away from these sodium containing processed foods. Consider shopping at your local farmers markets, health food stores, or grow a garden, it will get you outside and the colors are more vibrant than the foods on our plates. Again, what we eat and drink will eventually make its way back into the natural cycle.
Imagine the population of where you live and the loads of dirty clothing that washed every day, possibly every minute of that day. These loads of laundry and the detergents used, add to the Total Dissolved Solids (TDS) levels as well. They contain Boron, phosphates to name a couple, but let us stay focused on TDS.
Detergents contain surfactants that remove dirt from our clothing and keep it suspended in the water. To keep these surfactants at a minimum and effectively clean in hard or soft waters, builders are added into the detergents. Builders, such as Sodium tripolyphosphate, remove calcium and magnesium in the clothing and water. This removal, allows the surfactants to get in there and do the cleaning. Remember that calcium and magnesium are salts that, in part, make up TDS.
So imagine when all the washing machines in your neighborhood cycle through and the water is emptied from the tub. Guess where the water containing surfactants, builders, dirt, calcium and magnesium ends up going? If you read the Food and Drinks article, you know where this is going. The water from the tub is heading toward the Water Reclamation Facility, (a.k.a.wastewater treatment facility).
When shopping for detergents, take the time and choose ones that are environmentally friendly. Research the web for loads, no pun intended, of information, just type in ‘Environmentally Safe Laundry Detergents’ and explore. There are a number of great web sites from people who have experimented with environmentally safe products, to creating their own recipes for cleaning laundry. If you really want to get into the Nitty -gritty of things check out www.epa.gov/saferchoice.
Water softeners are typically used to remove calcium and magnesium minerals from hard water. The removal of these two minerals helps with the effectiveness of laundry detergents, internal pipe scaling, and taste. Calcium carbonate is the main measure of the hardness in water, and the levels of classification are shown on the chart. Cherokee Metropolitan’s drinking water falls in the ‘Moderately Hard’ classification at an average of 100 mg/l.
Water softeners work by exchanging calcium and magnesium ions with sodium ions (salt). This exchange happens in the resin cylinder that contains plastic beads with a negative charge. This comes into play because calcium, magnesium and sodium all have positively charged (+) ions. As water passes through the negatively charged resin it attracts the stronger positive ions contained in the calcium and magnesium. Sodium ions are then released into your drinking water. Once the resin is saturated, there is a strong sodium (salt) based flush cycle, which strips away the stronger ions by scouring. The flush cycle and subsequent rinse cycle use the sodium based water, and leave the lesser of the ions coating the resin, starting the cycle again. These cycles increase the Total Dissolved Solids (TDS) that go down the drain and to the Water Reclamation Facility, (a.k.a.wastewater treatment facility). Cherokee’s Board of Directors passed Resolution 14-06 to prohibit water softeners within the district. This resolution was set in place to lessen the impact of TDS from reaching the treatment facility.
Decades of farming can influence the levels of Total Dissolved Solids (TDS, or salts) contained in drinking water supplies. Our drinking water comes from rivers, streams, lakes and underground aquifers. When there is runoff from rain or over irrigation of crops fields TDS will eventually influence these water sources. So how does growing crops add TDS to these sources? Besides water being the universal solvent and dissolving the minerals already contained naturally in the soil, there is the application of fertilizers. Fertilizers increase crop growth and help supplement soils deficient in these minerals (nutrients).
There are two different types of fertilizers, organic and inorganic fertilizers. Organic fertilizers come from composting, the decay of natural food scraps and natural wastes. These fertilizers may not contain a sufficient amount of nutrients required for healthy crop growth. Inorganic fertilizers are made from chemical compounds, and the three main nutrients are phosphorous, potassium, and nitrogen. Plants love these nutrients the most. Secondary nutrients are sulfur, calcium, and magnesium. Micronutrients are boron, cobalt, copper, iron, manganese, molybdenum and zinc. These nutrients (minerals) make up TDS, which through the application of fertilizers and irrigation can make their way into drinking water sources and add to natural TDS levels.
Manufacturing of items we use in our daily lives create by-products. These by-products will vary with the type of industry and could include metals from electroplating. By-products influence TDS levels in wastewater that are eventually received at a Water Reclamation Facility, (a.k.a.wastewater treatment facility).
Pretreatment programs help regulate industrial users by monitoring what additions are being made to water related processes at each facility. Industrial processes include adding acids, bases oxidizers, reducers, coagulants and final neutralization chemicals. The pretreatment department of the District is working with those industries to reduce each of these additives to the least amount possible and still achieve the desired outcome for the specific process
The Pretreatment division of Cherokee and the industrial users work together to establish Best Management Practices (BMP’s). BMP’s are a specific set of procedures that a business will use to fine-tune each industrial process. These practices help regulate the amount of each material additive needed in a process, minimizing the final discharge to achieve lower Total Dissolved Solids (TDS). As an added benefit to the use of BMP’s, industrial chemical costs can be reduced as well. Industries in the Cherokee Metropolitan District contribute 1.6 % of the overall TDS concentration received at the wastewater treatment facility.