{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/108628"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/108628","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Effects of installing point-of-use filters intended for lead removal on drinking water quality","abstract":"Defects in the aging drinking water distribution system can lead to elevated concentrations of toxic metals and harmful microorganisms that pose a risk to human health. Premise plumbing systems can be sites of elevated lead concentrations from lead service lines and are favorable environments for biofilm-forming opportunistic pathogens. To comply with state law requiring no more than 5 parts per billion (ppb) of lead in school drinking water, school administrators installed point-of-use (POU) filters made of activated carbon and ion exchange media in classroom sinks. Before and after common stagnation periods at the school (e.g., overnight, over-the-weekend), water samples were collected from a spigot where water enters the school and from sinks with and without POU filters. Lead, residual chlorine, particles (0.1-50 µm), bacteria, temperature, pH, and total organic carbon were measured. Lead concentrations in all unfiltered samples were below 2.25 ppb, but post-stagnation, over half of filtered samples exceeded 5 ppb. The filters effectively removed free chlorine (99% reduction), and residual chlorine decayed with stagnation. There were higher concentrations of particles and bacteria in filtered samples than in unfiltered samples, especially post-stagnation. Neither of the opportunistic pathogens tested for (Legionella pneumophila and Mycobacterium tuberculosis) were detected. Temperature increased with stagnation, pH decreased with filtration, and total organic carbon was steady across all sample conditions. Installing new filters did not significantly change the filters’ effects on lead concentrations, free chlorine removal, or particle counts. This study revealed that the POU filters in this school did not remove lead after a stagnation period. Filters removed residual chlorine throughout their one-year lifetimes and trapped particles and bacteria which were then released after stagnation. A 5-minute flush of filtered taps reduced lead concentrations, particles, and bacteria.","abstract_html":"Defects in the aging drinking water distribution system can lead to elevated concentrations of toxic metals and harmful microorganisms that pose a risk to human health. Premise plumbing systems can be sites of elevated lead concentrations from lead service lines and are favorable environments for biofilm-forming opportunistic pathogens. To comply with state law requiring no more than 5 parts per billion (ppb) of lead in school drinking water, school administrators installed point-of-use (POU) filters made of activated carbon and ion exchange media in classroom sinks. Before and after common stagnation periods at the school (e.g., overnight, over-the-weekend), water samples were collected from a spigot where water enters the school and from sinks with and without POU filters. Lead, residual chlorine, particles (0.1-50 µm), bacteria, temperature, pH, and total organic carbon were measured. Lead concentrations in all unfiltered samples were below 2.25 ppb, but post-stagnation, over half of filtered samples exceeded 5 ppb. The filters effectively removed free chlorine (99% reduction), and residual chlorine decayed with stagnation. There were higher concentrations of particles and bacteria in filtered samples than in unfiltered samples, especially post-stagnation. Neither of the opportunistic pathogens tested for (Legionella pneumophila and Mycobacterium tuberculosis) were detected. Temperature increased with stagnation, pH decreased with filtration, and total organic carbon was steady across all sample conditions. Installing new filters did not significantly change the filters’ effects on lead concentrations, free chlorine removal, or particle counts. This study revealed that the POU filters in this school did not remove lead after a stagnation period. Filters removed residual chlorine throughout their one-year lifetimes and trapped particles and bacteria which were then released after stagnation. A 5-minute flush of filtered taps reduced lead concentrations, particles, and bacteria.","abstract_has_math":false,"creators":["Clark, Gemma Giovanna"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Environ Engr in Civil Engr","degree_department":null,"school":null,"contributors":["Nguyen, Thanh H","Liu, Wen-Tso"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2020,"date_issued":"2020-10-07T22:44:41Z","date_published":"2020-10-07T22:44:41Z","updated_at":"2026-07-22T22:24:48Z","subjects":["Drinking water","point-of-use filtration","lead","residual chlorine","bacteria"],"languages":["en"],"rights":["Copyright 2020 Gemma Clark"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/108628","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Nguyen, Thanh H","Liu, Wen-Tso"]},{"key":"dc:creator","label":"Author","values":["Clark, Gemma Giovanna"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2020-10-07T22:44:41Z","2022-10-07T22:44:53Z","2020-07-21","2020-08"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Environ Engr in Civil Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Drinking water","point-of-use filtration","lead","residual chlorine","bacteria"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2020 Gemma Clark"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/108628"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Defects in the aging drinking water distribution system can lead to elevated concentrations of toxic metals and harmful microorganisms that pose a risk to human health. Premise plumbing systems can be sites of elevated lead concentrations from lead service lines and are favorable environments for biofilm-forming opportunistic pathogens. To comply with state law requiring no more than 5 parts per billion (ppb) of lead in school drinking water, school administrators installed point-of-use (POU) filters made of activated carbon and ion exchange media in classroom sinks. Before and after common stagnation periods at the school (e.g., overnight, over-the-weekend), water samples were collected from a spigot where water enters the school and from sinks with and without POU filters. Lead, residual chlorine, particles (0.1-50 µm), bacteria, temperature, pH, and total organic carbon were measured. Lead concentrations in all unfiltered samples were below 2.25 ppb, but post-stagnation, over half of filtered samples exceeded 5 ppb. The filters effectively removed free chlorine (99% reduction), and residual chlorine decayed with stagnation. There were higher concentrations of particles and bacteria in filtered samples than in unfiltered samples, especially post-stagnation. Neither of the opportunistic pathogens tested for (Legionella pneumophila and Mycobacterium tuberculosis) were detected. Temperature increased with stagnation, pH decreased with filtration, and total organic carbon was steady across all sample conditions. Installing new filters did not significantly change the filters’ effects on lead concentrations, free chlorine removal, or particle counts. This study revealed that the POU filters in this school did not remove lead after a stagnation period. Filters removed residual chlorine throughout their one-year lifetimes and trapped particles and bacteria which were then released after stagnation. A 5-minute flush of filtered taps reduced lead concentrations, particles, and bacteria.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2022-08-01","The student, Gemma Clark, accepted the attached license on 2020-07-20 at 14:20.","The student, Gemma Clark, submitted this Thesis for approval on 2020-07-20 at 14:23.","This Thesis was approved for publication on 2020-07-21 at 08:54.","DSpace SAF Submission Ingestion Package generated from Vireo submission #15696 on 2020-10-02 at 15:33:55","Made available in DSpace on 2020-10-07T22:44:41Z (GMT). No. of bitstreams: 2 CLARK-THESIS-2020.pdf: 2334218 bytes, checksum: 239f19a262de745de9080e5159ac276e (MD5) LICENSE.txt: 4208 bytes, checksum: f5abcb540f60bf59def0e40c4d0ab7fe (MD5) Previous issue date: 2020-07-21","Embargo set by: Seth Robbins for item 116255 Lift date: 2022-10-07T22:44:53Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Effects of installing point-of-use filters intended for lead removal on drinking water quality"]}]}],"canonical_facts":{"dc:contributor":["Nguyen, Thanh H","Liu, Wen-Tso"],"dc:creator":["Clark, Gemma Giovanna"],"dc:date":["2020-10-07T22:44:41Z","2022-10-07T22:44:53Z","2020-07-21","2020-08"],"dc:description":["Defects in the aging drinking water distribution system can lead to elevated concentrations of toxic metals and harmful microorganisms that pose a risk to human health. Premise plumbing systems can be sites of elevated lead concentrations from lead service lines and are favorable environments for biofilm-forming opportunistic pathogens. To comply with state law requiring no more than 5 parts per billion (ppb) of lead in school drinking water, school administrators installed point-of-use (POU) filters made of activated carbon and ion exchange media in classroom sinks. Before and after common stagnation periods at the school (e.g., overnight, over-the-weekend), water samples were collected from a spigot where water enters the school and from sinks with and without POU filters. Lead, residual chlorine, particles (0.1-50 µm), bacteria, temperature, pH, and total organic carbon were measured. Lead concentrations in all unfiltered samples were below 2.25 ppb, but post-stagnation, over half of filtered samples exceeded 5 ppb. The filters effectively removed free chlorine (99% reduction), and residual chlorine decayed with stagnation. There were higher concentrations of particles and bacteria in filtered samples than in unfiltered samples, especially post-stagnation. Neither of the opportunistic pathogens tested for (Legionella pneumophila and Mycobacterium tuberculosis) were detected. Temperature increased with stagnation, pH decreased with filtration, and total organic carbon was steady across all sample conditions. Installing new filters did not significantly change the filters’ effects on lead concentrations, free chlorine removal, or particle counts. This study revealed that the POU filters in this school did not remove lead after a stagnation period. Filters removed residual chlorine throughout their one-year lifetimes and trapped particles and bacteria which were then released after stagnation. A 5-minute flush of filtered taps reduced lead concentrations, particles, and bacteria.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2022-08-01","The student, Gemma Clark, accepted the attached license on 2020-07-20 at 14:20.","The student, Gemma Clark, submitted this Thesis for approval on 2020-07-20 at 14:23.","This Thesis was approved for publication on 2020-07-21 at 08:54.","DSpace SAF Submission Ingestion Package generated from Vireo submission #15696 on 2020-10-02 at 15:33:55","Made available in DSpace on 2020-10-07T22:44:41Z (GMT). No. of bitstreams: 2 CLARK-THESIS-2020.pdf: 2334218 bytes, checksum: 239f19a262de745de9080e5159ac276e (MD5) LICENSE.txt: 4208 bytes, checksum: f5abcb540f60bf59def0e40c4d0ab7fe (MD5) Previous issue date: 2020-07-21","Embargo set by: Seth Robbins for item 116255 Lift date: 2022-10-07T22:44:53Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/108628"],"dc:language":["en"],"dc:rights":["Copyright 2020 Gemma Clark"],"dc:subject":["Drinking water","point-of-use filtration","lead","residual chlorine","bacteria"],"dc:title":["Effects of installing point-of-use filters intended for lead removal on drinking water quality"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Environ Engr in Civil Engr"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:48Z"}