October 10, 2019 | by Ashley Hanson
How our Washington dairy conserves precious water
It’s going to take more than shorter showers to fix our water woes — something agriculturalists know all too well. I grew up on a dairy that my grandfather Richard Ziehnert has been operating in Elk, Wash. for more than 50 years. He likes to say farmers are the original water recyclers. It’s certainly true on our farm, and with good reason.
Not only is water an expensive resource, but MIT researchers estimate that by 2050, nearly 52 percent of 9.7 billion people will live in water-stressed areas. Plus, the USDA found that U.S. agriculture uses 80 percent of the country’s ground and surface water. We don’t take this lightly on Darilane Farms. From how we design our barns to how we manage our crops, we constantly strive to conserve water. Here are eight steps we take to recycle water on our dairy.
1. From water to milk
Like all life, cows need water to thrive. Yet, as my grandfather notes, they also turn it into a nutritious food source containing calcium, protein, phosphorous, potassium, iodine and vitamins B2 and B12. The average lactating (milk-producing) cow will drink 35 to 45 gallons of water a day, according to the University of New Hampshire, depending on their breed, the climate in which they live and how much milk they’re producing.
The average person living in the U.S., by contrast, can use up to 100 gallons of water per day, according to the United States Geological Survey. While we tend to be fairly inefficient, cows use the water they drink (plus feed) to produce on average six to seven gallons of milk a day — an average 87.2 percent of which is comprised of water. Turning water into food is a pretty obvious way that we optimize our water use on the dairy, but there’s a lot of recycling that goes on behind-the-scenes as well.
2. Recycled cooling water
The plate cooler above (the equipment resembling a xylophone) uses water to cool down milk, which is critical from a safety and quality perspective. But it definitely doesn’t go to waste. After milk leaves the cow at her body temperature, 98 degrees Fahrenheit, these plates move it towards the bulk storage tank, pushing cold water in the opposite direction. This cools the milk to about 52 degrees before it enters the bulk tank, where refrigeration brings the temperature down to 38 degrees within four hours.
We store all the water used in the plate cooler to clean our facilities. Every day, our farm pumps about 8,000 gallons of well water to be used in the milking herd and the parlor. Nearly all of it is recycled as flush water.
3. Flushing the barns
Different dairies have different ways of keeping their barns clean. At Darilane Farms, we take a multi-pronged approach to ensure the most efficient water use. First, we scrape away as many solids as possible, using a tractor bucket to clean the barn floors without using water. Then we flush out the barns with recycled water while the cows are being milked in the parlor. Grooves in the floors not only make it easier for cows to walk, but are also oriented in a way that optimizes flushing. From here the water travels to our lagoon system, which consists of three different pools that store and separate flushed effluent — preparing it for later use.
4. Filtering for fertilizer
It may look like there’s a prehistoric Gill-Man lurking in our lagoon, but really it’s just manure. In the first lagoon stage, solids float to the top and the leftover liquid makes its way to the next stage through a filtering system. The second pool (pictured above) brings the solid count down even more before water moves into the third stage, where it’s nearly solid-free. We call this brown water. Original name – I know. We then store this to be used later as fertilizer for 1,500 acres of alfalfa and barley. It takes more than just the recycled manure water to feed these plants though.
5. Capturing water runoff
Our farm is located east of the Cascade Mountains and two hours south of Canada, which means we receive a significant amount of moisture during the winter and spring months — around 16.52 inches of rain and 45 inches of snow annually, according to US Climate Data. We have to catch and recycle as much of this moisture as possible, since we can’t let water contaminated by manure run off into local waterways. It’s our responsibility to manage this water well and optimize our use of it. That’s why we design our barn roofs with a slant, which allows us to direct water and snow runoff to the same lagoon system mentioned above. From there it is filtered and stored with the other effluent.
6. Back to the fields
We spread lagoon water on our fields twice a year: once before the ground freezes in October or November and after the frost in the spring. A pump brings up the water through a long hose, which is pulled along by a tractor using discing equipment. This process mixes manure water into the soil as it’s applied to fields. This directly integrates all the beneficial nitrates, phosphorous and other essential nutrients found in manure into the soil while adding moisture. That last piece is extra important to us because we don’t irrigate our fields (also called dryland farming). Not all farms can manage without irrigating, but my grandfather says those who do depend on irrigation to grow crops and feed their herd are also excellent water recyclers.
7. Farm to feed bunk
The water we spread on the fields is used to grow feed for the cows. We grow alfalfa for silage, which provides the energy cows need to maintain health and produce milk. Then we add barley and other commodities for protein, which contributes to the milk’s nutrient density. This diet would be impossible without water. But on our farm, sustainable water management is a non-negotiable commitment we make as stewards of the land, water and animals in our care. In a way, according to my grandfather, we’re simply mimicking the cows — the ultimate recyclers. As long as we provide water, bring them meals, take care of their health and clean up after them, they do all the work. But there’s one more way we can help reduce water use.
8. Chocolate milk
“I drink less water and more chocolate milk,” my grandpa says. That counts…right?