The use of natural resources such as water in food production is a sustainability issue that continues to be on the radar of many farmers, scientists and consumers. In many regions of the world, water scarcity is on the rise as the demand for food production increases.
We’ve discussed how farmers use strategic irrigation practices on a regular basis and in times of drought, as well as how we as consumers can save water at home. But we thought we’d further explore other sustainable water-use practices at various points along the food supply chain.
Agile Ag Water
Let’s dive into water reuse on the farm. Of course, growing crops needs a notable amount of water to ensure productivity, but farmers aim not to waste any. Part of proper crop-growing and wise water use is linked to irrigation techniques, which allow water to move from one location to the next. Water not absorbed into the ground for crops can collect at the low end of furrows, border strips and basins. This wastewater is also referred to as irrigation tailwater. A certain amount of tailwater runoff is needed to ensure adequate penetration of water and irrigation efficiency, but the additional tailwater can be safely reused. Another source of agricultural wastewater, albeit a bit more indirect, is runoff from centralized plant facilities processing crops harvested from the field.
Both of these sources of wastewater can be reclaimed and used on neighboring farms or on the farm where it was generated. Wastewater that collects at the low end of furrows can be used for the irrigation of fields at lower elevations without filtration or purification treatments and without pumping. With pumps and collection systems, the runoff can be stored in ponds for later reuse as needed.
Agricultural wastewater from food processing plants typically contains a significant amount of organic matter, which may need to be filtered out or inactivated. However, in some cases these wastewaters can be used for soil conditioning and irrigation. They can help farmers improve the soil’s organic content, moisture-holding capacity, nutrient content and productivity. However, application of these wastewaters to the fields must be done with great care to avoid runoff and groundwater contamination.
Making Food, Saving Water and Taking Names
Now let’s look further down the “food road” and see how water can be saved after food leaves the farm. Many food and beverage plants reuse process wastewater onsite while still maintaining safety and quality. The majority of wastewater in food production facilities is used in non-food contact contexts, such as irrigation of landscaping, truck washing, cooling towers and warehouse floor washing. However, in some cases water can be reused in boilers, evaporators or chillers. Depending on how the water will be reused, it may require processing steps in order to remain safe.
For beverage producers including breweries, dairies, and soft drink, juice or bottled water plants, there are more opportunities to safely reuse process waters, simply because these products are made mostly of water. Both food and beverage companies employ water use monitoring systems (such as flow meters and leak detection systems) and can calculate their water-use ratio (the amount of water to produce a product versus the water contained in the final product) to see where the water is going in the plant and to minimize any waste.
No Waste, No Foul
Employing these methods on the farm and in manufacturing facilities can have a big impact on conserving natural resources in our food supply chain. Not only do these reuse strategies save water, but they also conserve energy, which water processing companies use to purify and pump water to farms and facilities, and also to treat sewage.
They add up to good things for a reliable food supply, and great things for the environment. We can all raise a glass (of water) to that!