Community Health Project: Looking for lead and nitrate pollution in the Bitterroot
This past spring semester, Bitterroot College students in an Environmental Science Class have been busy. They took on a Community Health Project that involved checking on the water quality not only in their own homes, but in local schools, other public buildings, the city’s water treatment facility, the Bitterroot River and some tributaries. A total of 40 water samples were collected and analyzed for nitrate and lead, according to George Furniss, a hydro-geologist professor at the college who teaches the class.
Furniss said that he came up with $500 to fund the project and told the students they would have to choose between looking for nutrient pollution or looking for lead pollution. To his surprise and delight, he said, “A student came in later with a $500 donation and said, ‘let’s do them both,’ so we did.”
According to Furniss, the results of the project did not turn up any serious problems with nitrate pollution, but some of the lead results do raise some serious concerns and in his opinion merit further study.
Twenty of the samples were used to measure Nitrate plus Nitrite in drinking water and 20 were used to measure lead in drinking water and to detect lead leachable to water in road materials.
Sixteen homes were tested, mostly occupied by Bitterroot College students and their families. Thirteen of the homes were found to contain Nitrate plus Nitrite in a range of 0.11 to 1.76 mg/L, (mg/L is the same as ppm). The State recommendations are that all drinking water should be less than 15 ppm with respect to Nitrate plus Nitrite.
“So all the homes we tested are easily far below the danger level,” said Furniss. Three of the homes tested found no detectable levels of Nitrate plus Nitrite. “Those results are even better,” said Furniss. The drinking fountain at Bitterroot College (Hamilton City water supply) was tested and found to have 0.31 ppm Nitrate plus Nitrite.
Three samples were used as quality control and quality assurance that were duplicates of each other and or were blanks of distilled water.
Six homes and six public buildings were tested for lead. One of the homes was found to be in the red danger level for lead with 77 parts per billion (ppb) lead, which means action should be taken to remove old lead plumbing before using water and in any case the faucets should be flushed for at least three minutes before drinking or cooking with the water. One home is in the take-action level at 6 ppb lead, which means the problem should be fixed or at a minimum water should be flushed from the pipes daily or any time before drinking or using for cooking. Two homes are in the warning zone at 1 and 2 ppb for lead. Lead should not be above 1 ppb, especially if children are exposed to drinking the water. Two of the homes tested were non-detectable for lead in the water.
Test results indicate a school building at Corvallis was 7 ppb lead, which means action should be taken to fix the problem or the water should be flushed daily, and every time before drinking. Test results indicate a school building at Hamilton was 15 ppb lead, and should be shut down if it is used for drinking water. A public church at Grandsdale tested 4 ppb lead and should be fixed or flushed daily and always flushed for three minutes before being used for drinking or for cooking.
The water discharge to the Bitterroot River from the Hamilton Water Treatment (sewer) Plant was tested and found to be 1 ppb lead. Lead levels discharged to the river should never be above 1 ppb.
In addition, a combination of six stream sediments and gravel road base materials were tested to look for leachable non-point-source lead pollution that could be reaching the Bitterroot River.
The 2014 TMDL report from Montana Department of Environmental Quality identified lead levels above standards for lead in the Bitterroot River downstream of Stevensville but after thorough investigation identified no source for the lead.
“With no explanation so far by anyone as to where the lead pollution is coming from,” said Furniss. “So we decided to try investigating.” He said there was one public comment in the TMDL report that offered a clue. It suggested that the lead could be leaching from gravels from the Curlew Mine that were used for road materials.
“Combined with some eyewitness reports about Curlew Mine gravels being used for road work in the area we decided to look into it,” said Furniss.
Using a Shake Flask method to determine if lead could be leaching from these stream and road materials and reaching the Bitterroot River, they found that three of the samples contained strong leachable lead signatures ranging from 12 ppb to 68 ppb lead, well above the estimated 6 ppb to 7 ppb background level for valley gravels mined in the valley for the purpose of road materials.
“This Shake Flask method is a qualitative measure and the lead leaching levels could actually be enormous because of the tonnage of sediments and road materials involved,” said Furniss.
The highest levels of lead were found along Indian Prairie Road and Meridian Road located near the mine in Victor.
One sediment sample was non-detectable for lead. For quality assurance, distilled water was used in a couple of samples and obtained a non-detectable result for lead from the lab analysis, which is expected.
“We found a significant amount of lead in the roads in the area of this abandoned mine,” said Furniss. “So we have documented the presence of lead in the area but we have still not identified the source.” He said further analysis would be needed to get a fingerprint for the lead samples and see if it matches the make-up of the ore at the Curlew Mine.
Energy Laboratories at Helena was used to analyze all of the samples. The total cost was $1000, all paid for by donations from students, faculty, and community members.
A video of the sampling and testing of the roadside samples is available on YouTube under the title A Community Project at https://youtu.be/ZkM2lop09FI
