MT. PLEASANT—Culinary water in Mt. Pleasant got through 2020 with flying colors, based on tests of more than 70 samples over the course of the year at a state-certified laboratory.
Summary results of tests for the presence of 14 substances, most of which cause health problems in high concentrations, were reported in the city’s annual Water Quality Report, which was published as a public notice in the June 30 Sanpete Messenger.
Test at eight locations
Colter Allen, the city water superintendent, says he and his staff draw samples for laboratory testing from eight locations in the city water system. They test one-half of the locations each month, which translates to 48 tests over the course of a year.
Those tests are supplemented by about 25 special tests each year.
The Water Quality Report showed the lowest and highest readings for each of the 14 substances. It also showed the maximum contaminant level (MCL) set by the U.S. Environmental Protection Agency.
Contaminants can get into water from a host of sources, including soil, rocks, fertilizer, human and animal wastes, metal works, oil refineries, septic tanks and corrosion of household pipes.
“All drinking water, including bottled water, may be reasonably expected to contain at least small amounts of some constituents,” the Water Quality Report says. “It’s important to remember that the presence of these constituents does not necessarily post a health risk.”
The fact a water sample comes close to or exceeds an MCL does not necessarily connote a dangerous situation. That’s because the United States has such high standards for drinking water.
The MCLs “are very stringent,” the report says. “A person would have to drink 2 liters (comparable to 2 quarts) of water at the MCL level for a lifetime to have a one-in-a- million chance of having the described health effect.”
There was only one measurement where Mt. Pleasant water exceeded the MCL on some tests. That was for “turbidity,” or cloudiness of the water. The characteristic is caused by water picking up soil as it travels to its destination.
Turbidity is measured by an instrument called a nephelometer. A light is shone through a bottle of water, and the nephelometer measures how much light scatters, rather than traveling in a straight line, as the light passes through the sample.
Tests high for cloudiness
The MCL for turbidity is 5 nepholmeter turbidity units (NTU). Mt. Pleasant’s water ranged from 0.5 NTUs (one-tenth of the standard) to 20.9 NTUs, a little more than four times the recommended maximum.
While clarity is a desired characteristic of water, cloudiness is one of the measures on the 14 tests that does not have any health effects, Allen said.
On all other measures, Mt. Pleasant water ranged from a fraction of the permitted level (such as one-third) to a tiny, tiny fraction, such as 1/17,000th of the standard.
No bacteria detected
Some of the most common water-born bacteria that can cause illness are coliform and a subtype of coliform called E-coli. On all tests, Mt. Pleasant water was rated “none detected” on these bacteria.
Eight of the 14 measurements were for inorganic substances, also referred to as dissolved solids.
One element that always causes concern is lead, which can affect cognitive development in children and cause heart and kidney problems in adults.
The highest lead reading in Mt. Pleasant water was 5.9 parts per billion out of an MCL of 15 parts per billion, which means the standard is 2.5 times the amount detected.
“Mt. Pleasant City cannot control the variety of materials used in plumbing components,” the Water Quality Report notes. “When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using any water for drinking or cooking.”
Another inorganic substance on the list is arsenic. A substantial amount of arsenic can poison a person very quickly. But trace amounts of arsenic are common in water.
Tests of Mt. Pleasant water for arsenic ranged from “none detected” to 0.7 parts per billion. The MCL is 10 parts per billion. So the level in Mt. Pleasant water would have to be 14 times higher to get to the MCL.
Other solids tested included selenium, copper, fluoride, nitrates, sodium and sulfate. On all of those except sodium, the MCL was 70 or more times the amount of the substance measured in Mt. Pleasant water. The EPA has not set an MCL for sodium, but the highest amount measured in Mt. Pleasant water was 15.7 parts per billion.
The total for all dissolved solids combined was 0.7 parts per billion out of an MCL of 80 parts per billion Mt. Pleasant could have had 142 times the amount of dissolved solids found in its water and still been within the standard.
Mt. Pleasant does treat its water with small amounts of chlorine and phosphate, Allen said. The chlorine is designed to kill bacteria. The phosphate helps keep pipes clean.
One of the 14 required tests is for trihalomethanes (TTHM), a byproduct of chlorine, which can be a carcinogen. TTHMs were one of the issues in contamination of water in Flint, Michigan.
In tests of Mt. Pleasant water, the highest level of TTHMs was 0.7 parts per billion out of an MCL of 80 parts per billion. Mt. Pleasant water would have had to have 114 times its present level of TTHMs to reach the limit.
Finally, two tests measure radioactive substances in water. One test measures “alpha emitters,” particles emitted by radioactive elements such as uranium and radium. The MCL is 15 “picocuries” per liter. A picocurie is an almost unimaginably small amount of radiation. The high for Mt. Pleasant water was 2.6 picocuries out of an MCL of 15 picocuries.
The other test for radioactivity is for radium 228, the substance, or isotope, left when uranium and thorium give off radioactive particles and rays. Mt. Pleasant’s highest level of radium 228 was 0.5 picocuries per liter out of an MCL of 5, or one-tenth of the maximum level.
“Our constant goal is to provide you with a safe and dependable supply of drinking water, the Water Quality Report says. “We want you to understand the efforts we make to continually improve the water treatment process and protect our water resources. We are committed to ensuring the quality of your water.”