Sources Of Drinking Water in Rapid City, South Dakota
Where does Rapid City get its water from? Rapid City uses a number of sources for our water system, including two infiltration galleries located along the Rapid Creek alluvium: the Jackson Springs Gallery and the Girl Scouts Gallery. We utilize eight wells that draw water from the Minnelusa and Madison Aquifers. Rapid City also utilizes surface water from Rapid Creek, which originates in the Rapid Creek drainage area west of Rapid City. This source includes the Deerfield and Pactola Reservoirs. Is Rapid City's water safe to drink? Does Rapid City have lead in the water? Does Rapid City put fluoride in the water?
Source: City of Rapid City, South Dakota
Contaminants Found in Rapid City's Water Supply
(Detected above health guidelines*)
3rd party independent testing found that this water utility exceeds health guidelines for this drinking water contaminant. The movie Erin Brockovich alerted the public to the great suffering the little town of Hinkley, California experienced due to hexavalent chromium in their drinking water. Today, Hinkley is little more than a ghost town thanks to continued water contamination, health concerns, and plummeting property values. Chromium (hexavalent) is a carcinogen that commonly contaminates American drinking water. Chromium (hexavalent) in drinking water may be due to industrial pollution or natural occurrences in mineral deposits and groundwater. What are the risks of drinking tap water with Chromium (hexavalent)? Cancer. A 2008 study by the National Toxicology Program, part of the National Institutes of Health, found that chromium-6 in drinking water caused cancer in laboratory rats and mice. That study and other research led scientists at the California Office of Environmental Health Hazard Assessment to conclude that chromium-6 can cause cancer in people. Find out more about this contaminant and how to remove it here.
3rd party independent testing found that this water utility exceeds health guidelines for this drinking water contaminant. Radiological contamination of water is due to the presence of radionuclides, which are defined as atoms with unstable nuclei. In an effort to become more stable, a radionuclide emits energy in the form of rays or high-speed particles. This is called ionizing radiation because it displaces electrons, which creates ions. The three major types of ionizing radiation are alpha particles, beta particles and gamma rays. Radiological contaminants leach into water from certain minerals and from mining. What are the risks of drinking tap water with Radiological contaminants? Cancer. Over and over again, regardless of the source, long-term exposure or brief exposure in high doses, leads to cancer. Cancers of the bone, liver, stomach, lungs, skin, kidneys, thyroid gland, and most other tissues are common, and medical science is still discovering other maladies that may be cancer-related. Find out more about this contaminant and how to remove it here.
Total Trihalomethanes (TTHMs)
3rd party independent testing found that this utility exceeds health guidelines for this drinking water contaminant. Total Trihalomethanes (TTHMs) are the result of a reaction between the chlorine used for disinfecting tap water and natural organic matter in the water. At elevated levels, TTHMs have been associated with negative health effects such as cancer and adverse reproductive outcomes. Now a study by government and academic researchers adds to previous evidence that dermal absorption and inhalation of TTHMs associated with everyday tap water use can result in significantly higher blood TTHM concentrations than simply drinking the water does. What are the risks of drinking tap water with Total Trihalomethanes (TTHMs)? Cancer. Studies from around the world including the United States & Europe have found that drinking tap water that carries Total Trihalomethanes increases the risk of developing cancer. In animal studies, all trihalomethanes cause liver, kidney and intestinal tumors. Find out more about this contaminant and how to remove it here.
What are the best type of filters to remove these contaminants?
Two dominant carbon filter choices are solid activated carbon blocks and granular activated carbon filters (GAC). Unfortunately, our tap water can contain tiny microscopic particles that impact your long term health. These tiny particles can also change the taste and smell of the water as well as contain microbiological organisms that can actually make people sick shortly after drinking. Fortunately, there are water filtration products that remove many of the impurities from water. These filters often use activated carbon; activated carbon is a form of carbon processed to have small, low-volume pores that increase the surface area available for adsorption of contaminants or chemical reactions with the contaminants causing them to adhere to the carbon. At Epic Water Filters we use solid activated carbon blocks for our filters which we believe is the superior way to filter contaminants out of your water. Below we explain why we chose to use solid activated carbon block filters instead of a granular activated carbon filter.
Granular activated carbon filters (GAC) have loose granules of carbon that look like black grains of sand. These black grains of carbon, are dumped into a container and the water is forced to travel through the container to reach the other side, passing by all of the grains of carbon. Solid block carbon filters, on the other hand, are blocks of compressed activated carbon that are formed with the combination of heat and pressure. These filters force the water to try to find a way through the solid wall and thousands of layers of carbon until they reach a channel which leads the water out of the filter. Both filters are made from carbon that’s ground into small particulate sizes. Solid activated carbon blocks are ground even further into a fine mesh 7 to 19 times smaller than the (GAC).
Flow Channels & Contact Time
As water continually passes through (GAC) filters, flow channels begin to develop that allow the water to flow around the carbon. Flow channels also develop between the granules of carbon themselves, leading to less effective filtration as there is less and less contact time between the water and the carbon. Solid activated carbon blocks, on the other hand, are much tighter and won’t even let microbial cysts like giardia and cryptosporidium (7 to 10 Microns in size) pass through the filter without getting caught in the millions of layers of carbon. Because solid activated carbon blocks are compressed under pressure, they have millions and millions of different sized pores that cause the water to take a long slow path to get through the filter, increasing the contact time that the contaminated water has with the carbon looking for a way through. During this contact time is when harmful contaminants like lead, adhere to the carbon and are removed from water. This happens during a process called adsorption, the other filtration method that solid activated carbon blocks use is called depth filtration. This is where the thickness of the carbon block filter comes into play to help remove contaminants as they have to pass through these thick carbon walls. The downside of solid activated carbon blocks is that they are often so tight that they can often get plugged up with organic and non-organic matter, forcing owners to replace them on a more regular basis. This is why when you are using a Brita water pitcher filter (GAC), the filter will keep going and going long after it has stopped removing any water contaminants. A good 5 micron sediment filter in front of your carbon block filter is a good way to extend the life of the solid activated carbon blocks and make it more efficient.
Solid Activated Carbon Blocks vs. Granulated Activated Carbon
The (GAC) filters are cheap and simple to manufacture, which is why most water filtration companies choose this method for manufacturing. Solid activated carbon blocks on the other hand take longer to manufacture and are more expensive to make but with this expense you will get superior contaminant removal because the water must take a more strenuous path through millions of layers of compressed carbon before it reaches your drinking glass.
The solid activated carbon blocks, like the one used in the Epic Smart Shield & Epic Water Filter pitchers, remove more contaminants than the (GAC) filters due to the larger surface area and the thickness of the carbon walls, this is why Epic Water Filters has standardized on the solid activated carbon block design for our water pitchers and our under the sink water filter. (GAC) filters do not do enough to reduce contaminants, this is why they are not used when there is a chance of bacteria or cysts in the water. They are truly not "Epic'' so that is why we have passed on the (GAC) filter design and let our competitors like Woder, Brita, Pur, and Invigorated Water use these loose packed carbon filters for sub-par contaminant removal.
With solid activated carbon blocks the contaminants are in contact with more carbon for a longer period and therefore have more time to remove stubborn contaminants like lead (Epic Pure Pitcher 99.9% removal), fluoride (Epic Pure Pitcher 97.8% removal), and PFCs (Epic Pure Pitcher 99.8% removal). Carbon blocks can remove chlorine more effectively, eliminate undesirable odors, and removal of endocrine disruptors like volatile organic compounds. (GAC) filters, on the other hand, have small particles that move around under the pressure of water so they do not have as much uniformity throughout and therefore less contact time with the water and less contaminant removal.
What About Whole House or Point of Entry Filters?
Whole house filters (as known as Point of Entry) are good for certain things, but you should understand what they are good for and what they are not good for before investing in one. Because of the high flow rate needed at the water’s point of entry into your home, whole home filters do not have much contact time with the water. This is why they are usually large in size, to increase the contact time between water and the filter media.
Whole home filters are generally set up in stages with some type of sediment filter first, followed by a large tank full of Granular Activated Carbon (GAC). There can be multiple stages in different systems but this doesn’t necessarily increase the removal capacity. It does, however, increase the price of the system. The water passes through the sediment filter first, which catches all of the dirt and debris and then runs through the large GAC tank to knock down chlorine. If you dig into the performance data sheet of some of these systems, you will see that the contaminants removed or reduced are not very impressive. This is why if you look at Whole House Water Filters vs Under Sink Water Filters, there is no comparison for contaminant removal. If you have the budget, whole home water filters or point of entry should just be your first line of defense in water filtration. It should never be the only water filter in your house. Anyone that tells you otherwise is probably trying to sell you a “Whole Home Filter.”
What About Reverse Osmosis?
RO filter systems do remove a lot of contaminants. In our opinion, there are 5 major downsides to a Reverse Osmosis System. The first major downside to RO systems is they are expensive. Most RO Systems cost 2x to 3x more than a carbon block system and usually have 4 to 6 small filters that need to be replaced each year. This means both the upfront cost and the yearly maintenance of the RO system will be higher. The second downside is that Reverse Osmosis wastes a lot of water. Each RO system wastes an average of 5 to 6 gallons for every 1 gallon of drinking water it produces. The third downside (and biggest downside of Reverse Osmosis in our minds) is that RO water filters remove trace minerals and other beneficial substances found in water that your body needs like calcium, manganese, iron and other important nutrients. This is why RO water is considered by many in the natural health world to be dead water and it is said that demineralized water is detrimental to general health due to vitamin and mineral depletion. The fourth major downside of RO systems is that after your water passes through the filter process, it sits inside of a steel drum that is lined with a butyl rubber bladder which is made from a polyisobutylene base. The filtered water sits in this butyl rubber bladder until it is used. All rubber bladders and plastic containers leach into water at some level. The fifth and last major downside regarding RO Systems is that because the RO filtration process strips out all of the good nutrients in water, some RO companies think they can add a "Remineralization Cartridge" at the end of the filtration process to replace all of the good stuff that mother nature originally had in the water (Yikes!). Also, most of these "Remineralization Cartridges" that we have seen in the marketplace come from China. Generally we have found that when scientists or business people try to mimic mother nature, they miss badly.
Solid carbon block filters do not have these issues. Epic Water Filters is committed to finding the best ways to filter contaminants out of your water for a healthier life and solid activated carbon block filters are what we believe to be the best overall filters. Have questions about your water? Great we love to talk about all things water related. Call us @ 720-600-0371 M-F 9am to 5pm MST or email our support team your questions firstname.lastname@example.org and we will get back to you as soon as possible.
*3rd party review of tap water provided by this water utility was in compliance with federal health-based drinking water standards. Health guidelines, mentioned on this page, were established by independent scientists who reviewed the scientific evidence, federal and state legal limits for drinking water contaminants, health advisories and risk assessments, and incorporated them all into the health guidelines referenced here. Information on source water was obtained from city water quality reports and may be subject to change based on your location and zip code. Please consult the latest water quality report for your neighborhood or home address for more accurate information. It’s important to note that only a handful of contaminants are required to be included in annual Consumer Confidence Reports or Water Quality Reports, and that there are hundreds of potentially harmful unregulated contaminants that aren’t accounted for by the EPA. Results of tests cited here were provided to an independent 3rd party by the state, as well as test information received from the U.S. EPA Enforcement and Compliance History database (ECHO). Water is very local so it is always recommended that you test your own tap water with a 3rd party laboratory. We have found 3rd party testing available from reputable labs between $150 to $400 but we do not give recommendations for labs. Currently we have not found a home water test kit that we would recommend and it is our opinion that TDS meters are not a reliable way to test water quality.
A hiker, blogger, and water quality expert.