top of page

Site Reclamation, In Situ Treatment Enabling a Unique Water Management Approach at Remote Former Uranium Mine


Former Uranium Mine


Remediation & Restoration, Site Operations, Microbiology & Genomics, Water Management

Key Words

Former, Uranium, Mine, Remediation, Reclamation, In Situ, Mine, Pool, Treatment, Level Management, Care, Maintenance, WTP, Operations, Passive, Water Treatment, High, Altitude, Remote, Site, Selenium, Uranium, Molybdenum, Water


Golden, CO

Project Summary

Rainy River Face of Lime WTP Looking East 2020.jpeg


The mine owner engaged Ensero to help them achieve ongoing environmental compliance and ultimately regulatory closure of a remote former uranium mine located near Denver, CO. Ensero responded quickly with a multi-faceted approach including reclamation, mine dewatering, and both in-situ and ex-situ water treatment measures. Our custom-designed water treatment plant uses direct Reverse Osmosis (RO) under pressure, to minimize fouling and metals precipitation, increasing RO membrane efficiency. Combining mine dewatering, RO treatment, and in situ treatment within the mine pool allowed the owner to demonstrate hydraulic control of water within the mine workings in three months. In situ mine pool metals reduction goals were achieved withinin six months. The water treatment plant consistently meets the uranium MCL of 0.03 mg/L. Ensero also completed reclamation work in a difficult, narrow canyon to minimize impacts to all stakeholders and protect the endangered Preble’s Jumping Mouse habitat. We continue to operate and maintain the WTP as well as perform care and maintenance activities as Schwarzwalder.

Rainy River Rapid Mix Tank, Lime Silo 2020.jpeg

On site passive water treatment pilot testing

Ensero's water treatment system design utilizes Reverse Osmosis pressure

Rainy River Aeration and Biomedia Close-up.jpeg
bottom of page