One Problem, No Single Answer
When we were last together, we discussed a presentation given to the Farm Bureau on nutrient problems in the Chesapeake Bay. Since that time, a number of rebuttals have been made with respect to the comments. Here is a brief commentary on some of those points.
First, beware of environmental presentations that use pounds over concentration. For instance, if you take a pound of sugar and put it into a gallon of water, you will taste it. But, if you put that same pound of sugar into 100 gallons of water, you may only have a slight change in taste. This is why concentration over pounds is important.
When a presentation or group focuses upon pounds, they are trying to influence public opinion with a less than candid perspective. Consider the rain we have received during these last couple of months. The extra rain may well have deposited large quantities of various nutrients, (both from natural and man-made sources) but does that mean algae blooms are occurring?
The next issue of importance is dissolved oxygen levels. This varies with depth and types of environments. In swamp-like areas, the water does not move with great force of mixing and dissolved oxygen levels tend to be lower.
But, the types of life that exist and grow in these environments is very different from those in mountain streams or rivers with lots of rocks. These environments tend to have much higher levels of dissolved oxygen.
Comparing these two kinds of environments is disingenuous. Groups promoting higher goals of dissolved oxygen levels may or may not account for these variations in environments. Their goal is to meet water quality standards for aquatic life that does not live in these areas. Hence, unless the basis of these goals are well defined for the public to understand, they may well be unrealistic.
Another aspect of importance is the models used to describe these environments. It was specifically stated within the presentation given to the Farm Bureau that models would not be used. The reason for this was displayed in the presentation; the models were consistently wrong and overestimated the problem.
As stated in the previous article, models are useful – we never would have put a man on the moon without a model. But, they are by no stretch of the imagination completely accurate. The world is far more complex than we can put into a computer model. That is why this presentation stated only actual data would be used.
There is no way to predict where the nutrients being measured came from. They may have entered the system from residential over application of lawn fertilizer, or from a recent rainfall event which stirred up the stream bed, thus releasing existing nutrient levels. Hence, the ongoing push and expense of “Cleaning up the Chesapeake” has a nice and well received idea, but actual implementation leaves quite a few questions unanswered.
One of those major unanswered questions is the setbacks required to ensure our streams remain as clean as practicable. As stated in the previous column, a one-size-fits-all solution is the governmental easy way out.
But, will it actually benefit the environment? The likelihood is slim. Because many environments do not require large setbacks, forcing that upon property owners will harm them and not benefit the environment. Couching this need under the rubric of protecting the Chesapeake only further muddies the waters of truthful governing.
We are now at a point where we can make reasonable estimates as to how far back from a stream edge protections need to take place. There is no consensus on whether grasses or trees are better edging, but we do have an idea of sedimentation rates based upon the types of soils and slopes. Forcing a large buffer or set back with such a poor understanding of nutrient deposition will generally cause more harm than good.
No one wants to harm the Chesapeake Bay. But, it is also unreasonable to enforce a knee-jerk solution that may not prevent the problem. This needs thorough review and realistic solutions rather than a one-size-fits-all, feel good solution.