## Facts

- EPA, acting under CERCLA, proposed (1988) and finalized (1990) listing B & B’s Hialeah, Florida facility on the National Priorities List (NPL) through informal rulemaking.
- Groundwater sampling found a contamination plume in the shallow layer of the Biscayne Aquifer, associated in part with on-site wastewater disposal pits.
- EPA scored the site at 35.35 on the original Hazard Ranking System (HRS) based solely on the groundwater migration pathway; 28.50 is the listing threshold.
- The HRS groundwater score included a “Targets” factor measuring threatened population, including “distance to nearest well/population served” and “ground water use.”
- Four public wellfields within three miles were connected to a regional system serving about 750,000 people; the wellfields drew primarily from deeper groundwater than the shallow contaminated layer.
- The regional authority did not use the wellfields as a regular supply source and pumped them briefly each day mainly to keep equipment operable.
- EPA counted the wellfields and the system population as targets, reasoning that the wells remained in service and capable of delivering water and that hydrogeologic conditions allowed migration from shallow to deeper zones; EPA cited trace contamination detected in deeper groundwater.
- Petitioners challenged both EPA’s use of the original HRS after SARA’s directive to issue a revised HRS and EPA’s inclusion of the wellfields/population in the targets calculation.

## Issues

1. Whether EPA could lawfully continue listing sites on the NPL using the original HRS after SARA required a revised HRS by a statutory deadline.
2. Whether EPA’s HRS scoring—especially counting the four wellfields and the associated regional population as “targets”—was arbitrary, capricious, or otherwise contrary to law.

## Decision

- The court denied the petition for review and upheld the NPL listing.
- The court held that precedent permitted EPA to continue using the original HRS until the revised HRS became effective.
- The court held that EPA reasonably treated the four wellfields and the connected regional population as targets under the original HRS definitions and record evidence.
- The court urged EPA to promptly consider delisting the site through administrative procedures.

## Legal Principles

- A statutory command to revise an agency methodology by a deadline does not, without an express prohibition, invalidate continued interim use of the existing methodology.
- NPL listings and HRS scoring are reviewed under the APA’s deferential arbitrary-and-capricious standard; courts do not reweigh technical risk judgments supported by record-based explanations.
- For HRS “targets,” EPA may count operable wells connected to a distribution system even if used as standby sources, when they are capable of supplying the public and the aquifer conditions support potential contaminant migration.
- A court may uphold an NPL listing on the administrative record while encouraging agency reconsideration (including delisting) based on updated information through the agency’s processes.

## Conclusion

The D.C. Circuit upheld EPA’s decision to list B & B’s site on the NPL, concluding that EPA could use the original HRS despite SARA’s revision mandate and that EPA’s inclusion of nearby wellfields and the regional served population in the groundwater “targets” score was reasonable under deferential APA review, while advising EPA to consider administrative delisting.


B & B Tritech, Inc. v. U.S. Env’t Prot. Agency, 957 F.2d 882 (D.C. Cir. 1992)