Systems and methods for the detection of low-level harmful substances in a large volume of fluid

A method for the detection of low-level harmful substances in a volume of fluid comprising:

• a) using a concentrator system to perform a method comprising:
• i) pumping at least 10 liters of fluid from a sample source through a filter and back into said sample source;
• said filter preventing the passage of at least one harmful substance;
• ii) diverting retentate from said filter into a container that is separate from said sample source;
• iii) recirculating at least part of said retentate in said container again through said filter;
• iv) circulating air to and from said container through an air filter;
• v) preventing the release of said retentate out of said concentrator system;
• vi) controlling the speed of a pump with a control system thereby maintaining a fluid pressure less than 25 PSI during said pumping of said fluid;
• vii) monitoring the quantity of retentate within said container with a control system and maintaining the quantity of retentate within a predetermined range comprising:
• (1) detecting a value of the volume or weight of said retentate;
• (2) controlling the amount of retentate diverted in said step of diverting retentate;
• and
• (3) selectively drawing in additional fluid from said sample source in order to maintain said quantity of retentate within said container within said predetermined range;
• and
• b) analyzing said retentate for the presence of at least one harmful substance.