Designing a hatchery’s water system

Tags: Hatchery management | Whitepaper

Written by Niek Yntema, August 27 2010

Designing a hatchery’s water system

The importance of water in the hatchery is well understood. Without water, washing/cleaning is practically impossible and many HVAC systems use water to provide optimal conditions for eggs, embryos, chicks and personnel. Sub-optimal water quality and insufficient water supply can cause losses, by undermining hatching results, contributing to mechanical breakdowns and presenting hygiene risks.

A properly designed water system is therefore critical to the success of any hatchery - and since good water is generally becoming more scarce and costly, it has become increasingly important to understand how to optimise the hatchery’s water quality and supply.

Typical water analysis. 

A good hatchery water system starts with knowing the quality of the water source. This is commonly achieved by (regular) laboratory analysis, with typical parameters including:

Acidity/alkalinity (pH): A pH of 7 is neutral. Below 7, the water becomes acid (can cause corrosion) while above 7 means the water is alkaline (can indicate hard water due to high levels of calcium). Generally a pH of 6-8 is acceptable - and pH can be corrected by adding chemicals.

Total hardness is an indication of hard water, which can cause limescale build-up, resulting in inefficiencies or the breakdown of equipment. The most common unit used is °dH (German degree) or mg CaCO3/l. Generally, 2-6°dH (35-107 mg CaCO3/l) is advised, with a maximum of 2°dH recommended for nozzle/spray humidification. Water softeners are used to reduce water hardness.

Suspended particles should be absent, as these will block pipes, nozzles etc. Suspended solids are removed by filters.

Microbial contamination should be absent. If water is contaminated, another source should be used. Disinfection can reduce contamination, but for example, using water contaminated with Pseudomonas, Acentobacter, Proteus, yeasts or molds - even after disinfection - for humidification is not advised.

Some elements in water are known for aggressive reactions which cause the discolouration of equipment. Commonly, the following thresholds are used: the total sum of chloride and sulphate (Cl & SO4) max 200 mg/l, Magnesium (Mg) max 50 mg/l, Iron (Fe) max 0.02mg/l. These elements require specific treatments. Extremely pure water (for example distilled or Reverse Osmosis water) is also known to be aggressive. It is therefore advisable to build a small bypass into the system.

Water treatment systems

Depending on the differences between the results of water analysis and the hatchery’s requirements, water treatment may be needed. Typically, water treatment is implemented using modular units:

  • Filtration eliminates suspended solids, usually by means of cartridge and/or sand filters;
  • Chemical treatment: usually anti-bacterial and anti-scaling treatments and/or a UV disinfection unit;
  • Water softener, which reduces water hardness by replacing calcium and magnesium with sodium;
  • Reverse osmosis, which uses membranes to separate dissolved salts, producing pure water;
  • Pumps, sensors and control units, to monitor equipment function, with buffer tanks to balance the difference between supply and demand. Reject or backwash water needs to be drained.

Water sources for the hatchery

In urban or industrial areas, water is generally supplied by the city’s main utilities provider or “city water”. The quality of city water varies, from excellent potable water (comparable with bottled water) to undrinkable, hard, turbid, chlorinated water. In remote areas or areas with insufficient city water availability, well or bore hole water provides an alternative, also typically known as hard water with high Iron content, that needs treatment before use. Depending on the difference between supply and demand capacity, buffer tanks may be used.

Water users in the hatchery

Water is requierd by the following main users/processes:

  • Potable water (for taps, human consumption, showers, toilets). Volume is mainly dependent on the size of the hatchery operation and its staff and the number of chicks being hatched per week.
  • Humidification (spray nozzles, rotating discs, fogging), consumption depends on the outside climate and on the volume of intake air.
  • Circulating systems (chilled or hot water) are filled once and only require replenishing in the case of spills or leaks in the system. Note: the risk of limescale and water aggressiveness increases with temperature, making hot water systems more vulnerable to the development of sub-optimal water quality than chilled water systems.
  • Production water (cleaning water for building, machines, trays, crates, trucks). Volume (expressed in litre/day old chick) varies significantly, depending on the hatchery’s cleaning protocols, which may be one or other of the following extremes, or anywhere in between:
    • Not manually removing debris (shells, fluff) prior to washing, using low pressure water hoses (1-3bar) and manually cleaning and rinsing
    • Removing debris prior to washing. Soaking, using detergent foam. Cleaning with mid-to-high pressure water jets (25-100 bar). Using high- pressure industrial tray/crate/trolley washers with internal water circulation.

As a general rule, 0.35 litre/day old chick is the unit we use to design a system that will meet the whole hatchery’s current and future water requirements. The scale of the production water operation clearly has the potential to increase or decrease this calculation - and therefore the system’s design - significantly.


  • Determine water use in the hatchery, with details of specific needs by water quality and volumes, ensuring that future expansion needs can also be met.
  • Have experts guide you in the proper analysis of the water and in the implementation of any water treatment and/or equipment needed.
  • Carry out regular analysis and inspections, to ensure that the water treatment plant runs effectively and efficiently, without overusing chemicals.
  • Determine water use in the hatchery, with details of specific needs by water quality and volumes, ensuring that future expansion needs can also be met.
  • Investigate methods for reducing water consumption, including an analysis of options to reduce dependency on the variable efficiency and effectiveness of manual washing
  • Try to find the best match between your water needs and your source of supply, as correcting any imbalance in volume or quality will require investment in equipment that, aside from its financial cost, also uses space, energy and chemicals and will require regular maintenance.
  • Avoid using rainwater for cleaning, as it may be contaminated with bird / rodent droppings.

Written by Niek Yntema

Productspecialist HVAC