本文描述了城市水源热泵（以公共饮用水为热源，并返回“已使用”的）所带来的问题向饮用水系统供水。概述了美国环保局的一项研究计划。第一阶段将涵盖管道流动和传热；随机需求；腐蚀电位；生物膜动力学；氯需求；储罐热效应；系统成本；以及风险分析。第二阶段将包括实验室和试点研究。第三阶段将包括实地研究。作者认为，水行业应继续向所有真正的闭环系统和一次性通过系统提供补给水，前提是管道受到防回流装置的适当保护。

This paper describes problems posed by the municipal water main source heat pump (which uses the public drinking water supply as a heat sink or heat source and returns the "used" water to the drinking water system. A research program by the USEPA is outlined. Phase 1 will cover pipe flow and heat transfer; stochastic demand; corrosion potential; biofilm dynamics; chlorine demand; storage tank thermal effects; systems costs; and risk analysis. Phase 2 will cover bench and pilot scale studies. Phase 3 will consist of field studies. The authors believe that the water industry should continue to provide makeup water to all true closed loop systems and one time through systems only if the line is properly protected by a backflow prevention device.