Minimum System Support Charge Per Unit: $4.64 per month (this includes no usage). First 2000 Cu. Ft. $1.09 per 100 Cu. Ft. Next 2000 Cu. Ft. $1.00 per 100 Cu. Ft. Next 4000 Cu. Ft. $ .93 per 100 Cu. Ft. Over 8000 Cu. Ft. $ .84 per 100 Cu. Ft.