Concentration Limitations Limitations satisfied on each Measurement Date on or after the Effective Date and during the Reinvestment Period if, in the aggregate, the Collateral Obligations owned (or in relation to a proposed purchase of a Collateral Obligation, owned and proposed to be owned) by the Issuer comply with all of the requirements set forth below (or in relation to a proposed purchase after the Effective Date, if any such requirement is not satisfied, the level of compliance with such requirement is maintained or improved after giving effect to the purchase), calculated in each case as required by Section 1.3 herein:
Net concentration means the difference between the concentration of a given substance in a sample taken of the discharge and the concentration of the same substances in a sample taken at the intake which supplies water to the given process. For the purpose of this definition, samples that are taken to determine the net concentration shall always be 24-hour composite samples made up of at least six increments taken at regular intervals throughout the plant day.