Rate Design – Customer Assistance Program Surcharge Calculation Method. The Settling Parties agree to continue utilizing the same method for calculating the Customer Assistance Program Surcharge. The calculation method is shown in the table below. The calculation shall use the number of “Participants” in the Customer Assistance Program as reported in the most recent month-end number in Great Oaks’ compliance filings in R.00-00-000. CAP Cost and Surcharge Calculation Meter Size Monthly Charge 50% Discount Yearly Discount Participants Totals 3/4" x 3/4" 1-inch