Discussion for the Chesapeake Bay Preservation Ordinance

Please continue the discussion by responding to this thread.

Chesapeake Bay Preservation Act Frequently Asked Questions

Admin wrote:Please continue the discussion by responding to this thread.

Chesapeake Bay Preservation Act Frequently Asked Questions

In regard to my email yesterday on the list serve (excerpt follows), I have contacted an author of EPA's RBP re: the buffer width metric used in stream assessments. I will relay his communication to forum participants. -- John

My email of 6/16/10..........
So where did the >18 m value come from? EPA’s Bioassessment Protocols reference the work of Barton, D. R., and W. D. Taylor, 1985 (Dimensions of riparian buffer strips required to maintain trout habitat in southern Ontario streams. North American Journal of Fisheries Management 5:364–378). I am not able to locate this paper, but elsewhere the 18 m value is noted as “adequate” not ”optimal”. A more recent study of Georgia streams, which are probably more indicative of our local streams than Ontario’s, found significant effects on trout populations when the buffer width is 15 m (50 ft) compared to 30 m (100 ft). Native trout may not be a representative indicator of County streams and rivers; I know of only one trout stream - Big Spring Creek. However, other sensitive species are certainly here.

I know the primary author of EPA’s Bioassessment Protocols and I plan to contact him regarding information on riparian buffer width. I know he will not recommend a single optimum width because many factors - hydrologic, geologic and biologic – affect how well buffers support water quality. Benefits of buffers include reducing the quantity and velocity of runoff, removing nutrients, sediment and toxic pollutants, providing carbon input (food) and moderating temperatures, all of which are essential for the survival of aquatic life.

I love these suggestions from Girard Girgick, especially his 4th point... I think rain gardens and other man made filtering tools for rain coming off of structures or for installation in key places near the mouths of streams are innovative. We use barley bales for our little pond, and it works great...

Girard's comments are as follows:

I must admit I have never understood it’s focus on land confiscation without compensation. I say this because I do not understand why it has never included, in the PWC or Fairfax versions, a requirement that the 100 foot taking had to drain toward the nearby water course. In my thinking the 100 foot should only apply if the surface water flow distance to a watercourse is 100’ or less. In fact, technically it could vary with slope. The 100 feet is a conservative estimate for a desired cleaning effect (75% silt and 40% nutrients per the Staff report). For example, at a 3% slope perhaps only 25 feet is needed so why take the other 75?

Points to Consider:
1. The buffers are a proxy for cleaning water and only one tool. Future buffers, i.e. those built by people subject to this act, do not clean the Chesapeake bay waters. The ordinance prevents some of the further degradation that happens with every single square foot of impervious cover that gets discharged at the same RATE as predevelopment but in greater volume. Each and every impervious square foot, (roof, barn, sidewalk, house, swimming pool parking lot, street) prevents groundwater absorption. Unless groundwater recharge is addressed, further decline will continue.

2. That being said, there are other tools that could be used to provide cleaner runoff, water and yet allow people to pursue their own dreams, such as a Fallingwater. Runoff from the hard cape can be routed through filters. Some hard capes can be made pervious and the stone sub-base used to store and recharge ground water In sediment and erosion control classes I was amazed at how effective leaf mulch bales are at silt removal. Inlet structures can incorporate bio filters, some inlet devices can incorporate charcoal filters to assure water quality. We can and should allow property owners to pursue better alternatives, if they can prove, and the burden of proof is on applicants, they are better.

1. Greener developments occur when curb and gutter are eliminated. Open ditch sections/vegetated swales are a better environmental route for subdivisions and parking lots. (Reference LEED site criteria) This creates lots of mini-riparian buffers as sheet runoff from each individual lot’s impervious area(s) is cleaned in the ditch before it enters a pipe or pond and gets to a stream. At low concentrations the pollutants decay in the soil through microbial actions. This puts the same cleaning effect far away from the stream and due to the sheet flow nature it is more easily managed.
2. There is currently a greater emphasis on rain gardens, (LEED) which perform best when used on sandy soils as a groundwater recharge tool. These don’t work well in clay soils on shale with bedrock 3’ down.
3. If the goal is cleaning storm water to save the bay, write a performance spec. This could catch fertilized land as well.
4. What we really need to do is to clean up our own mess. If every existing homeowner was required to create a groundwater recharge sized for that homeowners share of public and personal impervious cover, the streams and rivers would be recharged by their restored fair share of groundwater flow. This would restore dendritic, ephemeral and perennial streams and thereby eventually restore the Chesapeake. Along the way the more constant stream flows would restore streamside aquatic and vegetative life. I always think I need to change me first.

A good ordinance should address these issues.

Well now, I have finally convinced myself to create my mulched groundwater recharge pits. My only concern is “Does decomposing vegetable matter create methane?

Thank You!

Gerry

Girard J. Gurgick, P.E., BSCE, MBA, Principal
G2EM
8000 Towers Crescent Dr. Suite 650
Vienna, Virginia 22182
GGurgick@Gmail.com
T: 703 761 4924 C: 703 302 9944 F: 703 761 4877

Sally:

Rain gardens, rain barrels, hay bales and the like are helpful in improving the quality of runoff. However, mountains of scientific literature show that the best prescription for our streams and rivers is to leave riparian environments intact. Cutting riparian vegetation and disturbing soils increases the volume and rate of runoff, the amount of siltation, nutrient concentrations and temperature of aquatic systems. No post-development bandaid performs as well and, without careful site-specific engineering, it can exacerbate the problem. An example is over-engineered storm water detention basins, which store water that would otherwise maintain base flow in streams. In the summer, thunderstorms can flush the water, now heated well above levels tolerant to many aquatic species, into streams. Another example is the oft-touted rain garden. This post-development fix is often under-sized and not maintained to accomplish efficient removal of nutrients. And what happens in cold weather months, when the plants are gone and the fall application fertilizer is washing unhindered to the storm drain and stream? In contrast, the leaf litter and detritus of undisturbed riparian buffers trap nutrients and removal is accomplished in the growing season.

It is ironic that you point out Girard's recommendation for groundwater recharge zones. The most important recharge zone for streams and rivers is in the riparian zone. Another reason to protect this valuable resource.

You asked earlier this week, if I had referenced any more literature of interest. I encourage you to read the articles posted to this web page - http://water.usgs.gov/nawqa/urban/html/findings/index.html
I would be happy to discuss your comments on these articles.

John, I am not disputing that buffers can work. I am saying that there is no study performed by Loudoun County to justify imposing the Chesapeake Bay Act and its inflexible regulations on our County. The regulations were developed for Tidewater Counties, and to massively try to apply them to the foothills of the Blue Ridge makes no sense. And there is not the scientific study performed for Loudoun to show that specific land in Loudoun will damage the Bay in a "substantial" way if not designated RPA, and further, there are questions about the only county study done, that says optimal buffers can be less than 100 feet on each side of our streams, and other information that seems to say that the assessment we did needed further evaluation.

I don't think you are going to convince me that we have the "proof" necessary to adopt this Ordinance. To give you an example, you may "know" that someone is guilty of a crime, but you can't just say I know this, you have to meet the legal standard or burden of proof.

To use the Chesapeake Bay Act, in my opinion, you need a scientific study proving the "necessity" of delineating these RPA's and a study showing that if we do not put all this land into RPAs that the Bay will be "substantially damaged." That is the standard of proof, and I think this Board of Supervisors has none, specific to Loudoun, and I think the stream assessment does not show any necessity to do this.

One speaker at the public hearing read the VERSAR study which was part of the County's assessment report. She testified:

"There are 8 metrics that make up the Virginia DEQ’s Stream Condition Index. We failed only in bugs:
Mayflies, stoneflies & caddisflies, & scrapers—comprising 3 metrics—gave Loudoun unexpected low scores. For the remaining 5 metrics, the 108-pageVERSAR report states: “the other metrics had a more normal distribution of values” (8-1).
In addition, Loudoun data are being compared to the “`least disturbed condition readily available in the state.’” (8-2) So our streams are to be judged against remote areas?
In the “WATER QUALITY” section (4-6), dissolved oxygen “levels at all sites were above the commonly accepted standard.” (4.3) (DO is needed for aquatic life.)
Under “8.2 HABITAT ASSESSMENT”, 94% of our streams were either average for above average. None were rated poor."

My question to you, is if this is litigated--which it will be if it is adopted-- is how does our Stream Assessment support the necessity of a 100 foot buffer on each side of all the drains that are designated on the Proposed RPA map (which shows about half the County as proposed RPA?)

All of the other studies you are quoting are going to be irrelevant in Court.

OUr Board needs a specific study to show OUR land is NECESSARY to buffer with 100 foot buffers, or there will be SUBSTANTIAL DAMAGE TO THE BAY. We don't have that and there is even controversy about whether our stream water is even as bad as some keep touting. If 94% is excellent or above average, then why do we need the drastic measure of putting so much of our land in buffers, especially after we just down zoned 2/3 of our county to minimum lot size of either 20 acres or 40 acres? That's not a lot of "development" to occur, compared to our land mass.

Also are you familiar with the Joint Legislative Audit and Review Commission of the Virginia Legislature, who studied the implementation of the Ches Bay Act, and found it was not effective? they recommended implementation of the Act be discontinued, is my understanding... they studied the science and the cost. I believe that many think the regulation of fertilizer is what we need to do instead of these massive buffers (at least in Loudoun.)

I cannot attach a copy of the Audit, but I will email it to you if you would like to look at the science and findings that this State Legislature Commission considered.