The 1976 Needs Survey for Category V (correction of combined sewer overflows) and Category VI (treatment and/or control of stormwater discharges) was developed using a well defined, consistent nationwide methodology. The Needs Survey developed current and 1990 capital and annual operation and maintenance cost estimates to attain three water quality criteria: Aesthetics, Fish & Wildlife and Recreation. A computer model, called the Needs Estimation Model for Urban Runoff, was developed from intensive work with the literature of a detailed analysis of ten specific urbanized areas. The model calculates the combined sewer and stormwater control needs for each urbanized area. These estimates are then summed on a state and territory basis to provide the national estimated needs for Categories V & VI. The methodology provides a reasonable and well defined estimate of the eligible costs for water quality control required by combined sewer overflows and stormwater runoff.