Superfund / NPL site · EPA Superfund SEMS through latest publishNPL Deleted

Lehigh Portland Cement Co.

This site has been deleted from the EPA Superfund National Priorities List — EPA's classification means construction-complete cleanup objectives were achieved, though monitoring may continue. Most-cited contaminant of concern: Arsenic.

700 25Th St Nw, Mason City, Iowa · ZIP 50401 · EPA ID IAD005288634

CLEANUP TIMELINE

Listing-date and cleanup-phase enrichment from EPA's per-site SEMS profile is queued for a follow-up ingest pass. Until then, this section will populate from EPA's published timeline data.

Anomaly engine

Notable Signals

No notable signals at this Superfund site for the current ingest. Cleanup-phase and SEMS-action flags are deferred to a follow-up engineering pass.

Contaminants of concern · per EPA SEMS

What's In This Site

Each row pairs a contaminant with the medium it was found in (the exposure pathway). Hover any named contaminant for an agency-cited health-risk summary. Cited count = number of SEMS decision records (RODs and related) that name the pair.

ContaminantPathwayCited
ArsenicHealth riskIARC Group 1 carcinogen via inhalation and ingestion. EPA MCL 10 µg/L; chronic exposure causes skin, lung, bladder cancer and cardiovascular disease. (IARC, EPA, ATSDR)Groundwater1
ChromiumHealth riskHexavalent chromium (Cr-VI) is an IARC Group 1 carcinogen via inhalation, causing lung cancer; trivalent chromium is far less toxic. (IARC, EPA)Groundwater1
LeadHealth riskNeurotoxin. Even low childhood exposure impairs cognitive development; chronic adult exposure damages kidneys and the cardiovascular system. (EPA, ATSDR)Groundwater1
Drinking-water linkage · SDWIS

Groundwater Systems Serving Communities Within 3 Miles

The 1 system below draw on groundwater (or mixed sources) and serve communities whose centroid sits within 3 miles of this site. Distance is to the served-city centroid — SDWIS does not expose individual wellhead locations, so this is a proximity screen, not a wellhead-impact assessment.

Water systemServesDistancePopulation servedSourceStatus
Mason City Water Department MunicipalMason City2.2 mi27,338GROUNDWATERUNRESOLVED

Methodology: served-city centroid (TIGER 2020) is used as the PWS coordinate. Source-water classification from SDWIS primary_source_code; only groundwater and mixed-source systems are queried. Click any system above for its full SDWIS profile.

Equity context · ACS 2018-2022 block-group demographics

Who Lives Near This Site

Mason City, Iowa (no Census block groups within 1 mile — falling back to host city; disparity scores aggregated by centroid containment): a population of 27,271. Why we surface this →

POPULATION SHARE
10.5%

Low-income

POPULATION SHARE
12.6%

People of color

POPULATION SHARE
4.5%

Under age 5

POPULATION SHARE
22.1%

Over age 64

Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror). NPL site proximity contributes to the national EJ pattern; indicator-level percentile and disparity scores are surfaced on the county page and the state page.

Source. EPA Superfund Enterprise Management System (SEMS) · retrieved 2026-05-07. SEMS is a federal public-domain dataset under 17 USC §105.

What this is not. We report EPA's published Superfund record — site listing, status, and contaminants of concern as named in EPA's decision documents. We do not perform site visits, independent air or water sampling, or current-state health-risk assessment. NPL listing reflects EPA's Hazard Ranking Score at a point in time; it does not by itself describe present-day exposure.