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  • The biological unit must be protected from grease and fats. Modern cooking uses light oils, which may not separate. The collection and containment of all forms of grease prior to the biological equipment is vital. Operate any grease system in full accordance with the manufacturer’s instructions.

  • Individual kitchen practices affect loads, i.e. leftovers on plates may be scraped into bins, or wet rinsed into system, the former to be encouraged, the latter should be discouraged or factored into the treatment plant design.

  • Premises serving beers may produce toxic caustic effluents due to the hygiene and cleaning regimes.

  • The proportion of wastes from some sources can produce an effluent which is difficult to treat, e.g. some Drive Through Fast Food establishments can have an effluent with a low organic content.

8 H o t e l s & R e s i d e n t i a l C e n t r e s Establish “style and type” of hotel e.g. Prestige (5), Bedroom only accommodation, Conference Centres, Resort Hotels with Sports and Spas, Treatment Centres, etc.

  • Calculate total loading based on occupancy of at least 2 people

per room.

  • Some hotels regularly have 4 occupants per room.

  • Consider and add other hotel activities and waste functions.

  • The volume/BOD figures are based on an expectation that

guests have an evening meal, drink and breakfast and that good kitchen practices are in place.

  • Add all other loads, considering non-resident uses, ie Lunches, Functions, Visiting Drinkers, Diners, etc.

  • Consider periodicity of loads.

  • Ensure residential and training centre loadings reflect the complete meal plan, i.e. allow for lunch and afternoon tea, sports, etc.

  • Special Events. Check provision of temporary facilities, e.g. summer marquees and allow for appropriate loading.

  • Consider any loads from outside catering.

9 L a u n d r i e s Excepting domestic premises, it is assumed that all laundry functions are additional.

  • For each premises, identify which laundry items are done in house or sent off site.

  • Calculate the laundry load on the basis of the number of machines and the period of use.

  • Sites with laundries must fit and maintain lint filters.

  • The chemical load (detergents) inhibits biological treatment, the laundry waste percentage of the normal maximum Flow usually needs to be less than 30% of the total load.

  • Where the laundry percentage >30%, manufacturers select equipment on a different basis.


  • As a guide, where the hydraulic load from laundries is between 1-10%, system size increases by 10%, 11-20% increases by 20%, 21-30% increases by 30%.

  • Excess/surplus detergents (above the recommended quantities) can affect the biological process.

  • Discharge quality may be improved if operators use low/zero phosphate detergents.

10 Toilet Blocks

  • Figures can also be assessed according to the sanitary equipment and control system installed.

  • Automatically flushed urinals use 10 litres per hour; a single flush should not use more than 1.5 litres.

  • Consider ladies and gents toilet facilities separately.

11 Sports Clubs

  • Calculate loadings on 100% usage for the sporting facility. The figure provided includes showering and toilet use by the sports person.

  • Consider also the non-sporting uses, i.e. spectators’ toilet use.

  • Add drinkers, social members and staff.

  • Add values for catering facilities.

  • Check normal and exceptional catering provisions.

  • A swimming pool with no associated sports centre may be calculated using the number of swimmers, assume a toilet use per person, and by adding values for showers and spectators. Check duration of visits and modify for extended use.

  • Consider separate treatment or disposal of backwash waters from ancillary equipment, such as types of filtration and disinfectant removal in swimming pools.

12 Golf Clubs

  • The values within the data table allow for light snacks and toilet use.

  • Calculate additional allowances for showers.

  • Add values for other catering facilities (if other than light snacks).

1 3 H o s p i t a l s The nature of the facility affects the design values. Some nursing homes have very high hydraulic loads as a result of the use of bedpans and their sanitation. Consider any disinfection equipment installed.

  • With drugs and hygiene requirements of hospitals adjust the

equipment size to compensate for treatability factors.

  • Disposal of unused/waste medicines is not permitted via the

treatment facility.

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