Congregate Shelter Capacity and Sanitation

ScopeSinks, and showers that many people need -- and the answer halves when a one-night evacuation becomes a two-week stay. Under the American Red Cross mass care standards a 24-48 hour evacuation shelter gives each person 20 sq ft of sleeping space, and a longer stay needs 40 to 60 or more for belongings, circulation, and some privacy. A 9,600 sq ft gym holds 480 people the night of the storm and 240 once it becomes a shelter for the displaced. The sanitation ratios follow the population and are the part of a shelter that fails first: 1 toilet and 1 hand-washing lavatory per 20 persons, 1 shower per 25, 1.5 gal per person per day of sewage capacity, 5 lb per person per day of solid waste, and one 30 gal lidded container per 10 persons. At 240 residents that is 12 toilets, 12 lavatories, 10 showers, 360 gal a day of sewage, 1,200 lb a day of trash, and 24 containers -- more than the restrooms near most gyms provide, and the gap a shower trailer and a row of portable units close. Ten showers at fifteen minutes each give 240 residents their turn in six hours of continuous use. The building's code occupant load is not suspended by an emergency; entered, it is checked and a larger shelter population is flagged. It does not address functional-needs space, medical, feeding, or pet areas, security, or HVAC and generator loads, and it does not replace the building official's occupant load or the fire marshal's review. The American Red Cross standards, the shelter manager, and the AHJ govern.

Formula or tablecapacity = floor(usable sleeping area / space per person) at 20 sq ft (evacuation, 24-48 h) or 40 to 60 sq ft (post-disaster); toilets = ceil(P / 20), lavatories = ceil(P / 20), showers = ceil(P / 25); sewage = 1.5 gal x P per day; solid waste = 5 lb x P per day; 30 gal containers = ceil(P / 10); shower cycle = P x 15 min / showers.

Source and editionAmerican Red Cross, Mass Care Standards and Indicators, as reproduced in the Florida State Emergency Shelter Plan (2018), Appendix F. The building's code occupant load is named as a cap; the shelter manager and the AHJ govern.

Free accessRatios from the Red Cross standards reproduced in a public Florida Division of Emergency Management appendix; division and rounding up only.

What governsEstimate. AHJ and licensed professional govern.

API field namesfloor_area_sqft, shelter_type, space_per_person_sqft, residents_count, code_occupant_load_count, existing_toilets_count, existing_lavatories_count, existing_showers_count, capacity_count, capacity_evacuation_count, capacity_60_count, toilets_count, lavatories_count, showers_count, sewage_gal_per_day, solid_waste_lb_per_day, containers_count, shower_cycle_hours

• 20 sq ft evacuation, 40-60+ sq ft longer stay personal sleeping space per personAmerican Red Cross Mass Care Standards (Florida SESP 2018, Appendix F)
• 1 toilet and 1 lavatory per 20, 1 shower per 25 each resident gets a 15 minute shower opportunityAmerican Red Cross Mass Care Standards (Florida SESP 2018, Appendix F)
• 1.5 gal sewage and 5 lb solid waste per person per day one 30 gal lidded container per 10 personsAmerican Red Cross Mass Care Standards (Florida SESP 2018, Appendix F)
• Wastewater storage 1.5 gal is the processing capacity; a shelter that must hold its wastewater (no sewer, a pumped reservoir) is sized on a 24-hour occupancy at 3 to 5 gal per occupant -- 1,250 gal for 250 persons -- per the same planFlorida SESP 2018, Appendix G, Section G.5.4