North Carolina Administrative Code › Title 15A - Environmental Quality › Chapter 02 - Environmental Management › Subchapter T - WASTE NOT DISCHARGED TO SURFACE WATERS › Section .0100 - GENERAL REQUIREMENTS › Section 02T .0114 - WASTEWATER DESIGN FLOW RATES

Current through Register Vol. 39, No. 2, July 15, 2024
(a)
				  This Rule shall be used to determine wastewater flow rates for all systems
				  governed by this Subchapter unless alternate criteria are provided by a
				  program-specific rule or for flow used for the purposes of
				  15A NCAC
				  02H .0105. Higher flow rates shall be
				  required where usage and occupancy are atypical, including those in Paragraph
				  (e) of this Rule. Wastewater flow calculations shall take hours of operation
				  and anticipated maximum occupancies and usage into account when calculating
				  peak flows for design.
(b) In
				  determining the volume of sewage from dwelling units, the flow rate shall be
				  120 gallons per day per bedroom. The minimum volume of sewage from each
				  dwelling unit shall be 240 gallons per day and each additional bedroom above
				  two bedrooms shall increase the volume by 120 gallons per day. Each bedroom or
				  any other room or addition that can function as a bedroom shall be considered a
				  bedroom for design purposes. When the occupancy of a dwelling unit exceeds two
				  persons per bedroom, the volume of sewage shall be determined by the maximum
				  occupancy at a rate of 60 gallons per person per day.
(c) The following table shall be used to
				  determine the minimum allowable design daily flow of wastewater facilities.
				  Design flow rates for establishments not identified below shall be determined
				  using available flow data, water-using fixtures, occupancy or operation
				  patterns, and other measured data.
Type of Establishments
Daily Flow For Design
Barber and beauty shops
Barber Shops
50 gal/chair
Beauty Shops
125 gal/booth or bowl
Businesses, offices and factories
General business and office
								  facilities
25 gal/employee/shift
Factories, excluding industrial
								  waste
25 gal/employee/shift
Factories or businesses with showers or food
								  preparation
35 gal/employee/shift
Warehouse
100 gal/loading bay
Warehouse . self storage (not including caretaker
								  residence)
1 gal/unit
Churches
Churches without kitchens, day care or
								  camps
3 gal/seat
Churches with kitchen
5 gal/seat
Churches providing day care or
								  camps
25 gal/person (child & employee)
Fire, rescue and emergency response
								  facilities
Fire or rescue stations without on site
								  staff
25 gal/person
Fire or rescue stations with on-site
								  staff
50 gal/person/shift
Food and drink facilities
Banquet, dining hall
30 gal/seat
Bars, cocktail lounges
20 gal/seat
Caterers
50 gal/100 sq ft floor space
Restaurant, full Service
40 gal/seat
Restaurant, single service
								  articles
20 gal/seat
Restaurant, drive-in
50 gal/car space
Restaurant, carry out only
50 gal/100 sq ft floor space
Institutions, dining halls
5 gal/meal
Deli
40 gal/100 sq ft floor space
Bakery
10 gal/100 sq ft floor space
Meat department, butcher shop or fish
								  market
75 gal/100 sq ft floor space
Specialty food stand or kiosk
50 gal/100 sq ft floor space
Hotels and Motels
Hotels, motels and bed &breakfast
								  facilities,
without in-room cooking
								  facilities
120 gal/room
Hotels and motels, with in-room cooking
								  facilities
175 gal/room
Resort hotels
200 gal/room
Cottages, cabins
200 gal/unit
Self service laundry facilities
500 gal/machine
Medical, dental, veterinary
								  facilities
Medical or dental offices
250 gal/practitioner/shift
Veterinary offices (not including
								  boarding)
250 gal/practitioner/shift
Veterinary hospitals, kennels, animal boarding
								  facilities
20 gal/pen, cage, kennel or stall
Hospitals, medical
300 gal/bed
Hospitals, mental
150 gal/bed
Convalescent, nursing, rest homes without laundry
								  facilities
60 gal/bed
Convalescent, nursing, rest homes with laundry
								  facilities
120 gal/bed
Residential care facilities
60 gal/person
Parks, recreation, camp grounds, R-V parks and
								  other outdoor activi
y facilities
Campgrounds with comfort station, without water
								  or sewer hookups
75 gal/campsite
Campgrounds with water and sewer
								  hookups
100 gal/campsite
Campground dump station facility
50 gal/space
Construction, hunting or work camps with flush
								  toilets
60 gal/person
Construction, hunting or work camps with chemical
								  or portable toilets
40 gal/person
Parks with restroom facilities
250 gal/plumbing fixture
Summer camps without food preparation or laundry
								  facilities
30 gal/person
Summer camps with food preparation and laundry
								  facilities
60 gal/person
Swimming pools, bathhouses and
								  spas
10 gal/person
Public access restrooms
325 gal/plumbing fixture
Schools, preschools and day care
Day care and preschool facilities
25 gal/person (child & employee)
Schools with cafeteria, gym and
								  showers
15 gal/student
Schools with cafeteria
12 gal/student
Schools without cafeteria, gym or
								  showers
10 gal/student
Boarding schools
60 gal/person (student &
								  employee)
Service stations, car wash facilities
Service stations, gas stations
250 gal/plumbing fixture
Car wash facilities
1200 gal/bay
Sports centers
Bowling center
50 gal/lane
Fitness, exercise, karate or dance
								  center
50 gal/100 sq ft
Tennis, racquet ball
50 gal/court
Gymnasium
50 gal/100 sq ft
Golf course with only minimal food
								  service
250 gal/plumbing fixture
Country clubs
60 gal/member or patron
Mini golf, putt-putt
250 gal/plumbing fixture
Go-kart, motocross
250 gal/plumbing fixture
Batting cages, driving ranges
250 gal/plumbing fixture
Marinas without bathhouse
10 gal/slip
Marinas with bathhouse
30 gal/slip
Video game arcades, pool halls
250 gal/plumbing fixture
Stadiums, auditoriums, theaters, community
								  centers
5 gal/seat
Stores, shopping centers, malls and flea
								  markets
Auto, boat, recreational vehicle
								  dealerships/showrooms with restrooms
125 gal/plumbing fixture
Convenience stores, with food
								  preparation
60 gal/100 sq ft
Convenience stores, without food
								  preparation
250 gal/plumbing fixture
Flea markets
30 gal/stall
Shopping centers and malls with food
								  service
130 gal/1000 sq ft
Stores and shopping centers without food
								  service
100 gal/1000 sq ft
Transportation terminals . air, bus, train,
								  ferry, port and dock
5 gal/passenger
(d) Design daily flow rates for proposed
				  non-residential developments where the types of use and occupancy are not known
				  shall be designed for a minimum of 880 gallons per acre, or the applicant shall
				  specify an anticipated flow based upon anticipated or potential uses.
(e) Design daily flow rates for residential
				  property on barrier islands and similar communities located south or east of
				  the Atlantic Intracoastal Waterway and used as vacation rental as defined in
				  G.S.
				  42A-4 shall be 120 gallons per day per
				  habitable room. Habitable room shall mean a room or enclosed floor space used
				  or intended to be used for living or sleeping, excluding kitchens and dining
				  areas, bathrooms, shower rooms, water closet compartments, laundries, pantries,
				  foyers, connecting corridors, closets, and storage spaces.
(f) An adjusted daily sewage flow design rate
				  shall be granted for permitted but not yet tributary connections and future
				  connections tributary to the system upon showing that the capacity of a sewage
				  system is adequate to meet actual daily wastewater flows from a facility
				  included in Paragraph (b) or (c) of this Rule without causing flow violations
				  at the receiving wastewater treatment plant or capacity-related sanitary sewer
				  overflows within the collection system as follows:
(1) Documented, representative data from that
				  facility or a comparable facility shall be submitted by an authorized signing
				  official in accordance with Rule .0106 of this Section to the Division for all
				  flow reduction requests, as follows:
(A) dates
				  of flow meter calibrations during the time frame evaluated and indication if
				  any adjustments were necessary;
(B)
				  a breakdown of the type of connections (e.g. two bedroom units, three bedroom
				  units) and number of customers for each month of submitted data as applicable.
				  Identification of any non-residential connections including subdivision
				  clubhouses and pools, restaurants, schools, churches and businesses. For each
				  non-residential connection, information identified in Paragraph (c) of this
				  Rule (e.g. 200 seat church, 40 seat restaurant, 35 person pool
				  bathhouse);
(C) a letter of
				  agreement from the owner or an official, meeting the criteria of Rule .0106 of
				  this Section, of the receiving collection system or treatment works accepting
				  the wastewater and agreeing with the adjusted design rate;
(D) age of the collection system;
(E) analysis of inflow and infiltration
				  within the collection system or receiving treatment plant, as
				  applicable;
(F) if a dedicated
				  wastewater treatment plant serves the specific area and is representative of
				  the residential wastewater usage, at least the 12 most recent consecutive
				  monthly average wastewater flow readings and the daily total wastewater flow
				  readings for the highest average wastewater flow month per customers, as
				  reported to the Division;
(G) if
				  daily data from a wastewater treatment plant cannot be used or is not
				  representative of the project area: 12 months worth of monthly average
				  wastewater flows from the receiving treatment plant shall be evaluated to
				  determine the peak sewage month. Daily wastewater flows shall then be taken
				  from a flow meter installed at the most downstream point of the collection area
				  for the peak month selected that is representative of the project area.
				  Justification for the selected placement of the flow meter shall also be
				  provided; and
(H) an estimated
				  design daily sewage flow rate shall be determined by calculating the numerical
				  average of the top three daily readings for the highest average flow month. The
				  calculations shall also account for seasonal variations, excessive inflow and
				  infiltration, age and suspected meter reading and recording errors.