High iron and manganese levels found in SSL waterAug 18, 2021 02:30PM ● By Bill Hardesty
By Bill Hardesty | [email protected]
On June 29, South Salt Lake issued a water system health advisory for customers of the SSL Drinking Water system, which are individuals north of 3300 South.
The individuals living south of 3300 South are customers of the Mt. Olympus Improvement District.
“On June 29, 2021, elevated levels of manganese [măng′gə-nēz′] were discovered in the South Salt Lake drinking water system. The high levels were found at hydrant testing sites,” the press release said.
It continued, “This is not a violation of a regulation. There are no federal public health regulations for manganese in drinking water. This notice is being sent because the measured concentration of manganese is above the EPA’s Health Advisory Level.”
Manganese is found in many foods. It is considered an essential nutrient for humans and animals. In addition, it helps to keep the body running properly.
The press release explained that “elevated manganese levels WILL NOT cause negative health effects for most people but can be harmful to infants under six months of age.” In addition, the elderly and individuals with liver disease should also avoid using tap water.
SSL suggested that tap water should not be used to prepare formula or other food for infants under six months of age. In addition, the elderly or individuals with liver disease should avoid using tap water to prepare food. For individuals affected, SSL provided bottled water.
SSL also noted, “brown discoloration in our water is caused by high iron content, not manganese. High iron content does not cause adverse health impacts.”
The press release made the statement that, “Lab results tested on July 1 have already shown a significant decrease in the level of detected manganese. The highest level of manganese samples taken on July 1 was .8. Ongoing testing will continue and be made available to the public until the .3 advisory level is reached.”
The question of why remained until the July 12 South Salt Lake City Council meeting. Jason Taylor, water division manager, explained the events that led to the health advisory. Taylor has been involved with the SSL water system for 22 years with 18 years as manager.
“No time during this incident were we out of compliance with any regulation or in violation of any rule,” Taylor said.
Taylor explained that SSL has experienced discolored water for some time. In the 1980s, SSL started to add chlorine to the water for disinfection. However, chlorine reacts with high iron and manganese in the groundwater. It also reacts to cast iron pipes which make up approximately 70% of the distribution system. The result of both situations is red-colored water.
In the early 2000s, SSL started a new entry process called sequestering. This process uses a chemical agent to encase the iron and manganese in the groundwater. It also created a protective layer on the inside of cast iron pipes.
Taylor explained, “I placed an order for more sequestering chemical in mid-June. Unfortunately, I was informed that there had been a shortage of the raw chemicals used to make our sequestering agent due to the pandemic. It was clear that we were going to run out of the chemical, and we would see an immediate increase in chorine in the water.”
Being proactive, SSL sent out a message via social media to affected customers. The Utah Division of Drinking Water saw the post and contacted SSL. Taylor said, “They were concerned that without the sequestering agent, there would be a possibility of leaching lead and copper out of our pipes. This action would make our water corrosive.”
The state required SSL to test the water for lead, copper, iron and manganese. Since SSL had to rush the samples, they decided to take the samples from fire hydrants. The state also required further samples using the first draw method the next day. This method requires samples to be taken from inside a residence or business at a kitchen or bathroom tap and only when the faucet has not been used for over six hours. The issue with this method is that officials need to rely on customers and often they forget.
When SSL provided the first samples, “They showed no increase of lead and copper, and that our water was only slightly corrosive. However, they did show elevated levels of iron and manganese.”
Taylor explained that this was expected because the samples were taken from fire hydrants. Fire hydrants pull water from the bottom of the pipe. Drinking water typically comes from the top. Iron and manganese usually float to the bottom. However, the division still required the health advisory and required SSL to take five additional samples throughout the system each week. As a result, SSL collected 38 samples over eight days using the first draw method.
“The highest sample was .0616 parts per million, which is approximately 1/5th of the levels set in the 10-day health advisory,” Taylor said. “The average of the 38 samples was .027 parts per million.”
When the results were sent to the state, they immediately removed the health advisory requirement on July 3.
Taylor mentioned that the city hired an engineering company in March to develop a unidirectional flushing system. The system will improve the ability to remove sediment from the system and reduce the amount of water needed to flush the system.