If you live in Reno, NV and you’re on a private well, you’ve probably had your well tested for water quality. If not, click here for information on how to do so.
If you just got your water test results back, you may be wondering what all the numbers and acronyms mean. They’re easy to read and understand with a little explanation.
Reading the Laboratory Result
Result: This is the level of the contaminant in your water. Results with the less-than symbol in front of them are referred to as non-detectable (some labs use the acronym ND instead). This means that if the contaminant is present in your water, it is at such a low level that the testing equipment can’t detect it. It’s as close to zero as it gets on a water test.
RL — Reporting Limit: The lowest level of a contaminant that the lab’s equipment can test for. Any levels below the reporting limit are non-detectable.
MCL — Maximum Contaminant Level: The level of a contaminant the EPA has deemed acceptable. Not to be confused with the MCLG (maximum contaminant level goal), which is the level at which a contaminant is known to be safe. Labs usually display the MCL on all contaminants that are a health concern and will show a “Failed” or “Over Limit” note on anything higher than the MCL.
Units of Measurement
Different labs use different units.
mg/L: Milligrams per liter is used for most contaminants that are not a health concern, and converts 1:1 with parts per million (ppm).
µg/L: Micrograms per liter is used for contaminants that are a health concern, because a small amount matters more. Converts 1:1 with parts per billion (ppb).
Converting from mg/L to µg/L is as simple as moving the decimal three digits to the right. To go from µg/L to mg/L, move it three digits left.
Some units are specific to certain measurements. CU (color units) measures the water’s color rather than a specific contaminant. NTU (Nephelometric Turbidity Unit) is what turbidity is measured in — since turbidity is the water’s ability to block light, it’s a characteristic rather than a contaminant, so the other units don’t apply.
Contaminants That Are Annoying Even Below the MCL
Hardness: Although it’s not a drinking water concern, total hardness will leave scale buildup on appliances and fixtures and cause dry, itchy skin at levels of 50 mg/L or more. Many people experience this when they move to Fernley, NV or Dayton, NV. They attribute the dry skin to our climate, but fixing the water makes a huge difference. You may also see scale buildup at even lower levels if silica is present, as we see in the Arrowcreek and Saddlehorn areas of Reno.
Iron: Iron can be a health concern in drinking water, but it will leave red stains on everything at levels as low as 0.2 mg/L. We often see low levels of iron leave stains on private wells in Washoe Valley, NV and the North Valleys.
Manganese: Much like iron, manganese will leave black stains and buildup in faucets and toilets long before it is a health concern. Levels of 0.02 mg/L or more should be considered for treatment. Manganese is common on wells in Palomino Valley, NV and Fallon, NV.
pH: Low pH can cause corrosion and leaks in plumbing and increase the levels of contaminants like copper and lead on your water report. Increased copper can cause blue staining. A pH below 7.0 should be corrected in homes with copper pipe or brass fittings. We’ve seen a lot of low pH in the Callahan Ranch area of Reno as well as Virginia City Highlands.
Contaminants Common to Our Area That May Not Show on a Test
Tannins: Tannins are tiny bits of organic matter suspended in the water that give it an off color — the same thing that creates the color in tea and wine. Tannins may show up on a water test as color, but iron also creates color, and it can be difficult to tell which you have from a test alone. We can run a couple of tests onsite free of charge to determine which is present and what type of treatment will actually work.
pH timing: pH can change rapidly between sample collection and lab testing due to variables like temperature and CO2 gas. Most labs will note that pH was analyzed outside its hold time and may be inaccurate. For this reason we always test pH onsite free of charge, to make sure we recommend the right system.
H2S: Hydrogen sulfide may be present in your water and won’t show up on a water test. H2S is a gas that can be naturally occurring or the result of sulfate-reducing bacteria. It gives water a rotten egg or sulfur smell. The best way to test for H2S is onsite, and we offer this free of charge.
Don’t see the answer you were looking for? Call our office at (775) 324-2001 and we’ll be happy to help.