7200 E. Hampden Ave., Suite 300, Denver, CO 80224 | 303.298.1644


Nathrop, CO

Mt Princeton Resort and Spa

This resort community in the Colorado Rockies uses water from a spring collection system to provide hot, mineral-laden water as an amenity to their guests, as well as for their domestic water supply. Routine water quality sampling revealed elevated levels of fluoride, a naturally occurring mineral which can be harmful to humans at high, sustained doses. The Colorado Department of Public Health and Environment (CDPHE) has asserted regulatory authority over the fluoride level, and will require the fluoride level lowered below the Maximum Contaminant Level (MCL).

Phelps Engineering Services  has assisted the client by coordinating with CDPHE in developing and understanding the improvement options and associated costs.

The system for providing hot and cold water to the community consists of several wells and springs, a heat exchanger and an elaborate system of pipes and pumps. This system has been constructed on an ad hoc basis over many decades. Using the few available drawings, Phelps Engineering Services, Inc. commissioned a land surveyor to locate surface features on the site, then performed a site visit to map and understand the water supply system. Phelps Engineering Services, Inc. then prepared a CAD-generated map of the community’s water infrastructure, showing all of the inter-connections. This map has proven valuable in talks with CDPHE, and regulators may now have a better understanding of what various compliance actions may entail. This map will also be useful for any future repairs and/or expansion of the water system.

Phelps Engineering Services, Inc. also conducted an analysis, culminating in a Technical Memorandum (TM) outlining the community’s technical options to obtain compliance. This TM analyses existing water quality monitoring data, estimates the flow requirements of the community, and examines two alternative water supplies, and two potential treatment methods. The alternate water supplies were found to be infeasible. Phelps Engineering Services, Inc. is currently working with equipment vendors to further examine the feasibility and develop conceptual level costs for reverse osmosis and activated alumina treatment.