Senate hears HB 707 proposing site‑specific setback and a five‑year time‑of‑travel standard for new landfills

Representative Kelly Potenza introduced HB 707 to require site‑specific setback rules for new municipal solid‑waste landfills and to change several technical criteria used in DES permitting.

"This bill is really tackling about 7 to 8 different pieces of the 800 rules," said Representative Kelly Potenza (Strafford District 19), describing the measure as an effort to update siting standards, incorporate time‑of‑travel science and strengthen protection for drinking water sources and surface waters. Potenza cited a JLCAR objection to the DES rules and said HB 707 fills gaps by placing specific siting metrics into statute.

The bill proposes multiple changes, including: a five‑year time‑of‑travel calculation for contaminants (or a minimum horizontal setback of 1,500 feet, whichever is greater); a hydraulic conductivity threshold for the upper 20 feet of native soil (Proponents sought 1×10^-4 cm/sec); a prohibition on imported soils as a workaround; a requirement for a guard or on‑site monitoring presence; a 100‑year storm standard with a 50% safety margin for stormwater design; and a 20‑foot minimum vertical buffer between the bottom of the landfill liner and bedrock in some provisions. Potenza said the measures are designed to ensure any new landfill would be "the last one we need for decades" and to reduce the chance that leachate or other contaminants reach groundwater or surface water before detection and remediation.

Supporters included hydrogeologists, environmental groups and municipal advocates. Muriel Robinette, a hydrogeologist with four decades of experience who testified for NCABC, said "I've not found a landfill yet in my 40 plus years career that didn't have releases of contaminants to the ground," and argued that siting a new facility where groundwater moves slowly will materially reduce risk. Representative James Gruber, a licensed civil engineer, testified the proposed 1×10^-4 threshold and a five‑year travel time are consistent with standards used in other states and with sound engineering practice.

DES Director (testifying in the record) defended the agency's recent rulemaking and cautioned against treating single numeric conductivity values as universally predictive. Director Wimsatt said, "to say that 10^-3 in any circumstance means that 3 feet per day ... is not an accurate statement," noting groundwater velocity depends on multiple site factors. He emphasized DES had strengthened rules in many areas and that the agency's holistic, site‑specific application review is designed to ensure detection and remediation before groundwater or surface water contamination crosses property lines.

Waste Management and some engineering witnesses raised operational concerns. Henry Veil (identified in the hearing as representing Waste Management) said several provisions could unintentionally affect permitted expansions at existing landfills; he pointed to potential impacts at an existing large facility where the permitted footprint currently relies on a 6‑foot separation from bedrock and where the bill's 20‑foot requirement would be problematic. Waste Management also highlighted that the 50% safety margin on a 100‑year storm could be effectively equivalent to designing for a much rarer extreme event and may be infeasible under current practices.

Municipal testimony raised staffing and cost questions. Sean Mulhall, city manager of Lebanon, said his city operates a landfill with roughly five years of remaining capacity and is preparing an expansion application; he said a 24‑7 on‑site staffing requirement would be difficult to meet in a smaller municipal operation and suggested remote sensors and monitoring could be more practical and effective.

Senators pressed authors and witnesses on the bill's scope and on whether the siting criteria would apply to expansions of existing facilities. Potenza and others said the intent is to cover new greenfield sites; committee members repeatedly requested explicit statutory language to clarify exemptions for existing municipal or privately permitted expansions. Waste Management and engineers urged that any final bill include clear exemptions or transition rules for ongoing facilities to avoid disrupting capacity and operations.

No final vote occurred during the hearing. Senators signaled willingness to work with sponsors and DES on technical fixes, in particular to clarify whether provisions apply to expansions, to reconsider the prohibition on imported soils and to refine the vertical buffer and stormwater design language. Potenza said she would participate in follow‑up drafting.