Lead in taps from public water sources

This story map provides a brief presentation and discussion of the water quality data collected from 43 taps on the COA campus during 2022. While 28 elements were included in the test, the report focuses mainly on lead levels from various campus taps. As COA receives water from a public water source, the Bar Harbor Water Division, the water that passes through campus taps is tested and treated to meet federal safety guidelines, yet lead from piping and building infrastructure may be contaminating drinking water between the public water line and the tap! Different taps within the same building may yield different amounts of lead and other metals. While 3 taps located on the outside of buildings (e.g. garden taps) yield elevated lead levels (4-10x the federal EPA limit of 15ppb), only one of the taps located inside of a campus building yields a level above this limit. Eight taps located inside classroom or office buildings yield lead levels above the recently updated limit of 4ppb for k-12 schools in Maine. Given these findings, we worked with Campus Buildings and Grounds committee to mitigate the issue using signage and installing filters.

Lead is a potent neurotoxin naturally occurring in Earth’s crust that has been used in various human-made materials like piping, plumbing fixtures, and paint. According to the EPA, lead tends to attack the brain, lowering IQ and hindering developmental growth in children. Pregnant women are also at increased risk of developing complications during birth. Adults with high-dose or chronic low-dose exposure to this metal in their drinking water may have cardiovascular, reproductive, or kidney problems.

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The Maximum Contaminant Level (MCL), set by the  EPA , is the maximum level allowed of a contaminant in water which is delivered to any user of a public water system in the USA. States can follow the federal guidelines or pose more stringent guidelines for public water systems within the state. For lead, the federal and state of Maine MCL is set at 15 ppb (µg/l), but recent studies suggest that  any presence of lead  can be toxic to humans. Many states, like California and Vermont, have opted to reduce the MCL to prevent further exposure. Through recent legislation, Maine Public Law 2019 Ch. 158, An Act to Strengthen Testing for Lead in School Drinking Water, the state developed a new limit of 4 ppb for all  k-12 schools across the state. During 2021-2022, a sampling of  school taps  revealed elevated lead levels in many locations throughout Maine.  

Lead pipes were ubiquitous in the country before their restriction in 1992 after the EPA signed the Lead and Copper Rule designed to protect household water. While new household piping does not contain lead, many older households retain leaded hardware. With high pH (basic) water, corrosion of pipes and leaching of metals is minimized; however, if  lower pH  (acidic) water is exposed to the pipes (part of the issue in the  Flint, MI crisis ), leaching of metals ___________________________________________ may occur. 

 We conducted a community  survey  to identify the commonly visited campus taps used for drinking water. Accordingly, we sampled water from the taps of thirteen buildings in addition to water dispensers from eight buildings across campus.

 For all taps, we collected a first-draw test, sampling immediately upon opening the tap. This test targets the water after it has been still in the pipes for days or, in some cases, overnight. This is likely the worst possible condition of the water and is also the most similar style to how people collect drinking water (right after opening the tap). In some locations, we collected a second sample after letting the water run for 5 minutes to compare it to the first draw test. We also collected cold and hot samples from water dispensers to see if the concentration of chemicals varied depending on the temperature of the water. The Trace Element Core Laboratory of Dartmouth College analyzed the samples and reported the concentrations of 28 elements: lead, arsenic, uranium, cadmium, iron, manganese, zinc, potassium, beryllium, magnesium, aluminum, phosphorus, sulfur, calcium, vanadium, chromium, copper, nickel, cobalt, selenium, molybdenum, silver, tin, antimony, cesium, and barium.

After getting our results back, we presented the first set of data to the Campus Planning and Building Committee and at the All College Meeting. And after showcasing what buildings were providing water with lead above the limit, the committee quickly installed filters for the residences with unsafe levels of lead in their water.

We presented a poster at the Acadia National Park Science Symposium, where we shared this study of the public water supply coming from a source within the park jurisdiction.

After our discovery of contaminated taps around campus during our first set of sampling collection, we decided to conduct a second survey with request of different office, classroom, and residential buildings around campus. Additionally, we added outside taps such as gardens, green houses, and the pier.

Similarly to the first set of data, we presented our findings to the Campus Planning and Building Committee. We shared our concerns with some taps that yielded above the MCL of 15 ppb, like some office buildings and the pier, which was provided by one of the office buildings that we raised awareness on due to levels of lead in the water.

The pier water connection was used to provide drinking water to the summer programs hosted at some nearby islands where COA manages research stations. After we shared our concern about the elevated lead levels in this source, the transport of water to the island from the pier was halted, and other alternatives were sought.

 Lead concentrations of all the samples collected on campus per source type, with three significant outliers in samples collected from taps: A&S Greenhouse (side), the pier, and the Seaside Garden behind Turrets. All yielded ~3 or more times higher than the MCL of 15 ppb, and ~12 or more times than the recommended limit for 12-k schools in Maine.

Water dispensers yield reliably low (all <1ppb) lead levels. These should be used as the primary source of drinking water on campus. 56 first draw samples were collected:  tap (n = 36), water dispenser (n = 18), water fountain (n = 2)

 By excluding the three samples coming from outside taps that have the highest lead concentrations, we can look more closely at the 53 samples with lead levels less than 20 ppb. Of these, seven taps located inside a building yield a lead concentration above the Maine school limit of 4 ppb, and only one yielded a level above the MCL of 15 ppb.

 A sample from a faculty apartment returned a slightly elevated lead level but below the MCL; Campus Buildings and Grounds personnel immediately installed a filter to remove the lead.  Similarly, bathroom taps and fountains with lead concentrations over the recommended limit now have signage directing users to other water sources.

Figure 3 shows the lead concentrations found in water provided by water dispensers depending on the temperature of the water. All samples yield lead concentrations below 1 ppb, demonstrating that water dispensers are the most reliable source of clean water regardless of the temperature or the building where it was collected. We put up signage around campus showcasing the location of the several water dispensers across COA.

We note that we did not test the different temperatures of water from the building taps, only from the water dispensers. It is possible that higher-temperature water from building taps may have elevated concentrations of metals, as has been demonstrated in other studies ( CDC ). It is recommended that you do not drink warm water directly from a tap but rather heat cold water for consumption.

We can also view the water quality of the samples grouped by the type and age of the building where each sample is located. Again, the three samples from outside taps with much higher lead levels are omitted from Figure 4 to focus on the majority of samples that have lower lead levels, <20 ppb. All samples from dorms and the cafeteria were below the limit. All taps from buildings built during the past 35 years have lead values less than 4 ppb.

Samples collected from classroom and office buildings show higher variability in lead concentrations in the water, with some samples above the ME school limit of 4 ppb and one sample from an office building with a concentration above the ME MCL of 15 ppb. Similarly, some classrooms and offices are located in buildings built 100+ years ago.

We compared our first draw test results with the metal concentrations present in the water after letting it run for 5 minutes. As prior studies show higher metal concentrations in water that has been sitting in taps for a while, we expected to see elevated levels of metals in the water that was collected immediately upon opening the tap.

Figure 5 demonstrates that there is a slightly higher exposure to lead when collecting water first thing in the morning because the water has been stagnant inside the pipes overnight. Instead, allowing water to run before consumption decreases lead exposure. All tested kitchens in the residences show low levels of lead. One building with a known lead issue yields concerning concentrations with the first draw.  This building office/classroom building yielded a first draw concentration of 8ppb; however, after 5 minutes, the lead concentration was 2ppb.

During our study, we identified that a historic building was providing water with elevated lead in their taps; the water dispenser in this building provided levels below the 4 ppb limit.

We first collected the concentrations of all the taps in this building except the basement; this sample was collected for our final round of sampling. We collected a sample from the basement where the water connection entered the building. This sample would allow us to determine whether the lead contamination was inside the building's pipes or if lead was already in the water prior to entering the building.

The lead concentration sampled at the conjunction between building pipes and water line yielded 3 times higher than the MCL and 11 times above the school limit for Maine. This helps us conclude that the water is contaminated with lead before entering the building. However, the threefold increase in the seaside garden sample denotes that there is also a pipe or fixture inside the building adding more lead to the water of outside taps.

During our third round of sample collection, we included houses owned by COA that are located outside of campus. All the samples yielded well below the MCL and the school limit for Maine. Out of the housing groups, houses located along Norris presented concentrations close to 0, whereas the housing group located in Birch Tree Lane yielded above 1 ppb, and one sample yielded above 2 ppb.

In summary, all the houses located off-campus provide water safe for consumption, with levels below the school limit of 4 ppb.

TUVA is a statistical software that allows you to easily manipulate and analyze the raw data by representing the data through graphs and charts. TUVA is free to use and easy to sign in. The buttons below will allow you to play and visualize the raw data from this study.

In this study, we identified the presence of lead and other metals in drinking water from the COA campus taps. While the source of the water, Eagle Lake, is the same for all campus water, each tap has its own chemical fingerprint. The majority of taps located inside buildings yield metal concentrations well below the different state maximum contaminant levels (MCLs). Where elevated metals at a tap were found, we posted a sign that directs people to another drinking water source.

Water from outside taps, such as in the gardens, presented elevated lead concentrations in the water. Do not drink water passing through outside taps. We suggest consuming water from the various water dispensers located throughout campus, as their filters help to maintain consistently low concentrations of metals regardless of variations in time of day, the temperature of the water, etc. Common drinking water contaminants like arsenic and uranium are not present in the water from the campus taps. The concentrations of these elements were all near the detection limit of the analytical instrument, which means that they are not a public health concern at the COA taps. However, these elements may be a concern for private well owners in the area (including students, faculty and staff who have household drinking water sourced from a groundwater well).

This work was supported by a National Institute of General Medical Sciences, Science Education Partnership Award (SEPA) Supplement (3R25GM129796-02S1), the Anne T. and Robert M. Bass Fund for Earth Systems and Geosciences, and COA work study.  Delphine Demaisey  provided assistance in preparing the data for the Tuva dataset used for data visualization and high school curricular materials. We are grateful to her for providing feedback on this report and on drafts of presentations of our findings. Building and Grounds personnel have been responsive and helpful throughout the process of this work and have acted quickly to mitigate any water quality issues found. We are grateful to those community members who completed our surveys and provided assistance and feedback during the process of sampling and reporting.

Author:  Ludwin Moran  in collaboration with  Sarah Hall