The solution to store, save and supply water
Saving water in dairies (part 1)
Water Saving Topics
Dairy farmers have identified many strategies to save water and the dairy industry learning packages also contain useful information. Details about many of these options to save water have been assembled in information sheets under the following headings.
- Holding Yards
- Plate Cooler and Cooling Towers
- Washing Vat and Milking Machine
- Washing Platform and Dairy Surfaces
- Other Areas
Holding Yards
Most of the water used for the dairy each day is used in washing the yards. Typically larger dairies use around 35,000L daily whilst the smaller herringbone dairies use around 5,000L. However water use varies hugely between farms. A survey by DPI Victoria in 2005 found some farms using less than 1,000L per day whilst others used in excess of 100,000L to wash down their dairies.
Reduce Amount of WaterMost of the water used for the dairy each day is used in washing the yards. Typically larger dairies use around 35,000L daily whilst the smaller herringbone dairies use around 5,000L. However water use varies hugely between farms. A survey by DPI Victoria in 2005 found some farms using less than 1,000L per day whilst others used in excess of 100,000L to wash down their dairies.
Check out the links below to see how you can save water when cleaning the yards.
- Alternative (bore) water supply
- Wash section closest to the shed only
- Wash yard less frequently
- Re-use water from effluent ponds
- Divert and use rainwater from yards
1, Alternative Bore-Water Supply
Description
Having a back up supply from a bore is very handy. Bore water can be used to supply yard wash water directly or shandied in with re-used yard wash water destined for disposal.
In many areas the water temperature is frequently constant throughout the year (about 16 - 18C) so can use bore water to supply the pre-cooler too.
Set-up costs are high - bore (about $5,000), submergible bore pump ($2-5,000), tank ($3,500), electrical and piping ($1000). Licensing from the water authority is generally required to construct a bore and then use water from a bore for dairy wash down.
Tips on Getting the Best Result
Fill header tank on off-peak power / wind mill.
Pros and Cons
Permanent fix and could use this for other purposes if water quality is OK.
Corrosion of pumps, cost, access to ground water, quality of water to spread on pasture, stains yards etc.
Issues in Making it Happen
Milk Quality
Nil - unless used to wash plant too.
Environment
Nil - may help reduce salinity of effluent discharge.
2, Wash Section Closest to the Shed Only
Description
Limiting the washing to the section of yard closest to the dairy can save water and limit the chances of cows slipping as they enter the dairy.
Use low pressure / high flow rate hoses. Give the whole yard a thorough hosing regularly to wash away the solids and keep drains open.
This can be an option if smooth concrete, steps or ramps make using scrapers too risky.
Tips on Getting the Best Result
Calm stock handling is important to limit injuries to cows and dirty udders. Works best if can use a scraper to remove most of the muck first.
Pros and Cons
Makes for a short clean-up time but care needs to be taken so drains and pumps don’t block-up.
Issues in Making it Happen
Labour
May increase time to clean teats but will decrease wash up time.
Animal Health
Small increase in mastitis risk.
Milk Quality
Small increase in sediment risk.
Environment
Semi-solid waste build up, flies, drains.
3, Wash Yard Less Frequently
Description
In some situations the frequency of yard washing can be reduced substantially. Periodic hosing is supplemented by using mechanical scrapers to remove most of the dry solids.
The cows need to have good footing on the concrete (dimpled or cobbled pattern). Careful stock handling and use of backing gate will minimise slips and injuries.
In drier times farmers have reported scraping the yard every 1-3 weeks, only giving it a complete clean when rain can soften the built up manure before a complete hose down.
Tips on Getting the Best Result
Cover drains and scrape most of the drier solids away. Break-up remaining solids, pre-wet yards and then flush remainder with a high flow rate wash.
The manure will be less of a hazard if the water can evaporate or drain away. Having dry weather and a yard slope of 2-3% will help.
Pros and Cons
Low cost option and may save time.
Care is required to preserve drains, pumps and manure distribution pipes. Yards may become very slippery. Stores of semi-solid waste must drain to effluent. Time required to spread waste.
Issues in Making it Happen
Labour
Saves time but may increase OH&S risks, may increase time required to clean teats.
Animal Health
May increase mastitis if cows splash udders and risks of slips and falls is increased.
Milk Quality
May increase sediment if cows splash udders.
Environment
Potentially reduce effluent volume and dilution.
4, Re-use Water from Effluent Ponds
Description
Pump water from second or third effluent pond and store for use in high flow rate yard cleaning systems. Commonly used for flood wash and hydrant wash systems with few problems.
The cost of setting up these systems very much depends on where the effluent ponds are situated – ponds, pipes, tank and effluent pump $20,000 - $25,000.
Using raw (untreated) effluent can make yards very slippery and increases odour. For a single pond system also need a pontoon and a pond stirrer (if crusting is a issue).
Tips on Getting the Best Result
Pump water into a storage tank overnight and use this to feed the wash pump.
If there is no crusting of the pond avoid using the pond stirrer when pumping water for yard washing. Use an effluent pump for this purpose not a water pump.
Avoid using the recycled water close to or inside the dairy and shandy ‘fresh’ water in with reused water to control salt levels.
Pros and Cons
Water availability.
Will get nutrient and salinity build up in re-used water – particularly in hotter climates. Smell can be an issue and concrete can get slippery.
Issues in Making it Happen
Labour
Although few problems reported there is the potential for OH&S risks if effluent water is used in systems that create aerosols (ie hydrant wash).
5, Animal Health
Nil as long as concrete is not slippery.
Labour
Salinity and nutrient build up in water causes issues for disposal. Odour problems occur too.
Divert and Use Rainwater
Description
The yard can catch a huge amount of rainwater [Litres= annual rainfall (mm) x area (m2)] over the year. This must be stored (or pumped) if not diverted away prior to entering the effluent system.
Diverters intercept waterflow between yard and sump. Metal bridge or valve types available. Useful in high rainfall zones where yards are cleaned twice daily. Collected rain water is suitable for washing yards.
Tips on Getting the Best Result
Easy to install if there is one drainage point from yard, need large sump, best if gravity can be used for rainwater diversion.
Pros and Cons
Reduce effluent volume, improve effluent digestion, capture water for other uses. Manually operated or by air ram.
Need a separate storage for rain water. Only works if the yard is cleaned between milkings.
Issues in Making it Happen
Labour
Remembering to change value if manual control
Animal Health
Nil
Milk Quality
Nil
Environment
Should reduce effluent storage problems.
To be continued
