.0401 DESIGN DAILY FLOW

(a) The minimum DDF for dwelling units shall be 120 gpd per bedroom or 60 gpd per person when occupancy exceeds two persons per bedroom, whichever is greater.

(b) DDF for facilities other than dwelling units shall be in accordance with Table II as follows:
TABLE II. Design daily flow for Facilities :

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Commercial Facilities

• Airports, railroad stations, bus and ferry terminals, etc.

  5 gal/traveler, food preparation not included

• Barber shops

  50 gal/chair

• Bars, cocktail lounges

  20 gal/seat, food preparation not included

• Beauty shops, style shops, hair salons

  125 Gallons per chair

• Bed and breakfast homes and inns

  Dwelling unit DDF based on Paragraph (a) of this Rule plus 120 gal/rented room which includes the following:

  Meals served to overnight guests

  Laundry for linens

  150 gal/room with cooking facilities in individual rooms

• Event Center

  5 gal/person with toilets and hand sinks up to 4 hrs

  10 gal/person with toilets and hand sinks up to 8 hrs

  15 gal/person with toilets and hand sinks greater than 8 hrs

  Add 5 gal/person with full kitchen

• Markets open less than four days/week, such as a flea market or farmers market

  30 gal/stall or vendor, food preparation not included

• Marinas with no holding tank discharge included

  30 gal/boat slip, with bathhouse

  10 gal/boat slip, wet slips or slips on dock

  5 gal/boat slip, dry storage or warehouse

• Motels/hotels

  120 gal/room includes the following: No cooking facilities in individual rooms other than a microwave or other similar devices

  No food service or limited food service establishment Laundry for linens

  150 gal/room with cooking facilities in individual rooms

• Offices and factories with no IPWW included

  12 gal/employee/≤ 8 hr shift

  Add 2 gal/employee/hr for more than 8 hr shift

  Add 10 gal/employee for showers

• Stores, shopping centers, and malls

  100 gal/1,000 ft2 of retail sales area, food preparation not included

• Warehouse that are not retail sales warehouses

  100 gal/loading bay or

  12 gal/employee/≤ 8 hr shift

  Add 2 gal/employee/hr for more than 8 hr shift

• Storage warehouse including self-storage facilities and does not include caretaker residence Item

  12 gal/employee/≤ 8 hr shift

  Add 2 gal/employee/hr for more than 8 hr shif

• Alcoholic beverage tasting areas with no process wastewater included

  200 gal/1,000 ft2 of tasting area floor space and includes glass washing equipment

  Food preparation and food clean up not included

  12 gal/employee/≤ 8 hr shift

Recreational facilities

• Bowling center

  50 gal/lane, food preparation not included

• Community center, gym∞

  5 gal/person plus 12 gal/employee/≤ 8 hr shift

  Add 2 gal/employee/hr for more than 8 hr shift or

  50 gal/100 ft2, whichever is greater

• Country club or golf course

  10 gal/person

  12 gal/employee/≤ 8 hr shift

  Add 2 gal/employee/hr for more than 8 hr shift

  3 gal/person for convenience stations

  Food preparation not included

• Fairground

  250 gal/toilet or urinal

• Fitness center, spas, karate, dance, exercise∞

  50 gal/100 ft2 of floor space used by clientele

  Food preparation not included

• Recreational park, State park, county park, and other similar facilities with no sports facilities

  10 gal/parking space

• Outdoor sports facilities, mini golf, batting cages, driving ranges, motocross, athletic park, ball fields, stadium, and other similar facilities

  250 gal/toilet or urinal, 5 gal/seat, or 10 gal/parking space, whichever is greater

  Food preparation not included

• Auditorium, theater, amphitheater, drive-in theater

  2 gal/seat or 10 gal/parking space, whichever is greater

  Food preparation not included

• Swimming pools and bathhouses

  5 gal/person domestic waste only, bathing load of pool may be used as an alternative method of sizing

• Sports facilities courts or other similar facilities

  250 gal/toilet or urinal or 50 gal/court, whichever is greater

Schools

• Day schools*

  6 gal/student with no cafeteria or gymnasium

  9 gal/student with cafeteria only

  12 gal/student with cafeteria and gymnasium

• After school program

  5 gal/student in addition to flow for regular school day

• Boarding schools

  60 gal/student and resident employee with laundry

Camps / Campgrounds

• Summer camps with overnight stays*

  60 gal/person, applied as follows:

  15 gal/person/food preparation

  20 gal/person/toilet facilities

  10 gal/person/bathing facilities

  15 gal/person/laundry facilities

• Day camps not inclusive of swimming area bathhouse*

  20 gal/person

  and

  5 gal/meal served with multiuse service or

  3 gal/meal served with single-service articles

• Temporary Labor Camp or Migrant Housing Camp with overnight stays*

  60 gal/person, applied as follows:

  15 gal/person/food preparation

  20 gal/person/toilet facilities

  10 gal/person/bathing facilities

  15 gal/person/laundry facilities

• Travel trailer or RV in an RV park*

  100 gal/space

• Recreational Park Trailer or Park Model Trailer 400 ft2 or less in an RV park*

  150 gal/space

• Bathhouse for campsites and RV park sites with no water and sewer hook ups with a maximum of four people per campsite

  70 gal/campsite

Food preparation facilities

• Food Establishments with multiuse articles*

  Open 6 hrs/day or less:
  25 gal/seat or
  25 gal/15 ft2 of floor space

  Open 6 to 16 hrs/day
  40 gal/seat or
  40 gal/15 ft2 of floor space

  Add 4 gpd/seat for every additional hour open beyond 16 hrs

• Food Establishments with single service articles*

  Open 6 hrs/day or less:
  20 gal/seat or
  20 gal/15 ft2 of floor space

  Open 6 to 16 hrs/day
  30 gal/seat or
  30 gal/15 ft2 of floor space

  Add 3 gpd/seat for every additional hour open beyond 16 hrs

• Food stand with up to eight seats, mobile food units, and commissary kitchens*

  50 gal/100 ft2 of food stand, food unit, or food prep floor space and

  12 gal/employee/≤ 8 hr shift

  Add 2 gal/employee/hr for more than 8 hr shift

• Other food service facilities*

  5 gal/meal served with multiuse articles

  3 gal/meal served with single service articles

• Meat markets or fish markets with no process wastewater included*

  50 gal/100 ft2 of floor space and

  12 gal/employee/≤ 8 hr shift

  Add 2 gal/employee/hr for more than 8 hr shift

Health care and other care institutions

• Hospitals*

  300 gal/bed

• Rest homes, assisted living homes, and nursing homes*

  150 gal/bed with laundry

  75 gal/bed without laundry

  Add 60 gal/resident employee with laundry

• Day care facilities

  15 gal/person open ≤ 12 hr shift without laundry

  Add 1 gal/person/hr open for more than 12 hrs per day

  Add 5 gal/person with full kitchen

• Group homes, drug rehabilitation, mental health, and other care institutions

  75 gal/person with laundry

• Orphanages

  60 gal/student or resident employee with laundry

Public access restrooms

• Convenience store, service station, truck stop*

  250 gal/toilet or urinal meeting the following:
  Open less than 16 hrs/day

  Food preparation not included

  Retail space not included

  325 gal/toilet or urinal meeting the following:
  Open 16 to 24 hrs/day

  Food preparation not included

  Retail space not included

• Highway rest areas and visitor centers*

  325 gal/toilet or urinal or

  10 gal/parking space,

  Whichever is greater

Institutions

• Church or other religious institution*

  2 gal/seat sanctuary only

  3 gal/seat with warming kitchen in same structure as sanctuary

  5 gal/seat with full kitchen in same structure as sanctuary

• Public or private assembly halls used for recreation, regularly scheduled meetings, events, or amusement∞* For churches, flow shall be in addition to sanctuary structure flow

  2 gal/person with toilets and hand sinks

  3 gal/person with addition of a warming kitchen

  5 gal/person with full kitchen

* Facility has potential to generate HSE

∞ Designer shall use the maximum building occupancy assigned by the local fire marshal in calculating DDF unless another method for determining DDF is proposed, including the justification for not using the maximum building occupancy.

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(c) The minimum DDF from any facility other than a dwelling unit shall be 100 gpd. For facilities with multiple design units, the minimum DDF shall be 100 gpd per design unit. The DDF of the facility shall be the sum of all design unit flows.

(d) DDF determination for wastewater systems with facilities not identified in this Rule shall be determined using available water use data, capacity of water-using fixtures, occupancy or operation patterns, and other measured data from the facility itself or a comparable facility.

(e) Where laundry is not specified for a facility in Table II, but is proposed to be provided, the DDF shall be adjusted to account for the proposed usage and machine water capacity. The applicant or a licensed professional shall provide cut-sheets for laundry machines proposed for use in facilities.

(f) HVAC unit or ice machine condensate, gutter or sump pump discharge, water treatment system back flush lines, or similar incidental flows shall not discharge to the wastewater system, unless a PE designs the wastewater system for these flows.

(g) Unless otherwise noted in Table II, the DDF per unit includes employees.

(h) Food service facilities and other facilities that are projected to generate wastewater with constituent levels greater than DSE, as defined in Rule .0402 of this Section, are identified in Table II with a single asterisk (*) as HSE. Any facility that has a food service component that contributes 50 percent or more of the DDF shall be considered to generate HSE. Determination of wastewater strength shall be based on projected or measured levels of one or more of the following: BOD, TSS, FOG, or TN. Table III of Rule .0402(a) of this Section identifies the constituent limits for DSE.

(i) Wastewater with constituents other than those listed in Table III of Rule .0402(a) of this Section may be classified as IPWW as defined in G.S. 130A-334(2a) on a site-specific basis.

(j) A request for an adjusted DDF shall be made in accordance with Rule .0403 of this Section.

History Note: Authority G.S. 130A-335(e); S.L. 2013-413, s.34; S.L. 2014-120, s.53; S.L. 2023-77, s.9.