can continuously or intermittently e g periodically at pre set time intervals monitor fluid quality or upon inquiry or operate based on stored data at the sensor sites 110 a 110 f depending on the data storage and communication capabilities of the sensor units 110 real time data has obvious advantages and it should be noted that most types of sensor units 110 contemplated above measure in real time whether continuously periodically or upon inquiry rather that taking samples and testing the samples at a later time additionally the smart nodes 332 may periodically or at the command of an operator inquire as to measured data from the sensor units 110 as communication protocols or information needs might dictate the centralized data collection as represented by the smart nodes 332 and the centralized data collection point 333 can be conducted over private or public networks e g vpn wan the world wide web including the internet dedicated telephone lines cellular networks or virtually any other form of communication for instance telephone land lines and telephone wireless networks can be utilized for a call up by the sensor units 110 for periodic interrogation by the smart nodes 332 or centralized data collection point 333 of the sensor units 110 additionally other communication protocols can be used including communications.