This referral requests assistance from DOJ to recover response costs incurred by EPA regarding investigation of releases of hazardous substances at and from the Hendrick Mining and Milling Superfund Site located in Boulder, CO. In June, 2010 the City of Boulder submitted an application to CDPHE under the Voluntary Cleanup Program (VCUP) to address environmental problems at the Site. The City proposes to excavate the secondary tailings pond and soils contaminated with lead and arsinic outside the tailings ponds areas and to consolidate these materials within the pronary tailings pond. The primary tailings pond will then be capped with an engineered cover that will withstand the infestation of prairie dogs. The City has requested Honeywell and Tusco share in the cost of implementing this remedy. The parties have been unable to reach a cost sharing arrangement and are currently in mediation.