One of the most significant environmental threats to the Shenandoah River is nutrient loading; too much of the stuff that makes plants grow (mainly nitrogen and phosphorus) getting into the river and making the tiniest of plants (algae) grow out of control. When the algae matures, dies, and decomposes it consumes oxygen from the water dramatically affecting all the fish and other creatures who depend on that oxygen in the water for their survival. This in turn throws the whole ecological balance of the river out of whack.
The Shenandoah Valley is one of the richest and most concentrated farming areas in the East. One major source of these excess nutrients comes from over fertilized farm fields. Soil can only take up so much nitrogen and phosphorus. A good portion of the excess ends up washing off the land and into the river. Fertilizer is expensive though, and farmers are not going to intentionally apply more than what’s needed, but if you get a hard rain right after application, or seasonal timing is off, everyone loses. Application timing is important as is how much to put where. Many farmers today are testing the soil in grid patterns, then programing that information into the GPS systems on their tractors to vary the amount of fertilizer application for different areas thus saving money and reducing nutrient run off. Another effective technique for capturing excess nutrients is to maintain a vegetative buffer of 35 to 50 feet along the edge of rivers and streams which helps absorb excess nutrients washing off the land.
A second major source of excess nutrients is run off from confined livestock feeding operations (such as cattle feed lots or commercial chicken houses which concentrates nutrient rich animal waste). Chicken litter waste from commercial chicken houses is the biggest problem. Most of this litter is spread on the land as a nitrogen rich fertilizer, but more litter is produced in the Shenandoah Valley than there is available farm land on which to spread it. With government cost share assistance most chicken farmers have built chicken litter storage buildings to help manage the waste and keep it from leaching into the river, and a fledgling system of shipping nutrient rich chicken litter out of the Valley has been established, but chicken litter is still consistently over applied to farmland in many areas out of convenience.
Using government cost share plans, most dairy farmers have constructed large storage tanks to store and manage the animal waste from their herds. And cattle farmers with feed lot operations need to locate those feed lots away from streams and in areas with vegetative buffers.
A third major source of excess nutrients comes from people themselves every time they flush the toilet. Older sewage treatment plants remove harmful sediment and bacteria from waste water, but most of the nutrients in the water pass through the system and end up in the river. And as the population increases, the nutrients increase. Fortunately, most sewage treatment plants in the Valley are being upgraded (with government help) to remove most of these nutrients from the waste water which is a big step in the right direction, but comes with a hefty price tag and will take time to complete. Many rural residents depend on individual septic systems, but these systems require periodic maintenance and eventually may fail resulting in untreated sewage leaching to the surface and running into creeks and streams which feed the river. Unfortunately, most home owners in rural areas have a poor understanding of maintenance requirements for septic systems. Out of site, out of mind.
As modern farms become ever more specialized and concentrated, it is important to factor in the environmental impact. Farmers receive a lot of criticism simply because they physically control a disproportionately large chunk of God’s green earth as compared to the rest of us. And generally speaking I think it would be safe to say most farmers are conservative and suspicious of government, but most farmers I know love the land and want to do the right thing for the environment. It’s a process, but in the end I think everyone realizes, “If you poison the environment, the environment will poison you”.