Ottawa, Illinois

===Areas still affected by radiation===
Sixteen areas of Ottawa are still radioactive.<ref>{{cite web |title=Ottawa radiation areas |url=http://www.toxicsites.us/site.php?epa_id=ILD980606750 |publisher=ToxicSites |access-date=5 October 2020}}</ref> The [[United States Department of Health and Human Services]] released a study,<ref>{{cite web |title=Ottawa Radiation Areas |url=http://www.atsdr.cdc.gov/HAC/pha/OttawaRadiationAreas/OttawaRadiationAreasPHA072506.pdf |publisher=United States Department of Health and Human Services |access-date=5 October 2020 |date=25 July 2006}}</ref> outlining areas where contamination by radium-226 (Ra-226), as well as emissions of [[radon-222]] (Rn-222), are at or above normal levels. These areas include homes, public areas, schools, and even a car sales lot that is housed directly over the old [[Radium Dial Company]] site. A score of 28.5/100 or higher qualifies an area for the Superfund National Priority List, and Ottawa's hazardous ranking score is 50/100.

The radium in Ottawa's water supply occurs naturally in water from deep wells across northern Illinois.<ref>{{cite web |title=Illinois State Water Survey |url=http://www.isws.illinois.edu/pubdoc/IEM/ISWSIEM2006-04.pdf |publisher=Illinois Department of Natural Resources |access-date=5 October 2020 |date=July 2006}}</ref> A reverse osmosis water treatment plant removes the radium so the city's tap water complies with federal regulations.<ref>{{cite web |title=Water Treatment Plant History |url=https://cityofottawa.org/water-treatment-plant-history/ |publisher=City of Ottawa |access-date=5 October 2020}}</ref>