Chlorine or Ultraviolet Disinfection?A case study in Small Flows compares a commercial chlorine tablet feeder with an ultraviolet disinfection unit for onsite systems. The systems were operated for nine months using biologically treated septic tank effluent. Both provided comparable results and experienced intermittent problems: the chlorine tablets did not dissolve uniformly and minerals collected on the lamp sleeve, eventually reducing its performance. The article discusses each unit’s performance measurements, reliability and constraints, maintenance requirements, and estimated cost of implementation and operation.Another article gives a rational method for determining design flows for cluster systems. Author Larry Stephens, P.E., discusses what factors
