Bill Wentzel - General Environmental Systems 2 ATTACHMENT

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GENERAL ENVIRONMENTAL SYSTEMS, INC.
April 6, 2014
Mr. Justin Bashaw
USAGE, Wilmington District
69 Darlington Avenue
Wilmington, North Carolina 28403 -1343
Email address: justin.p.bashaw @usace.army.mil
RE: Environmental Assessment (EA) for A Demonstration Project Showing the Impact of Floating In -Lake
Long- Distance Circulators in B.E. Jordan Lake, dated March 2014
Hi Justin,
I am a resident of Raleigh as well as Vice President of General Environmental Systems (GES), lake and
reservoir aeration specialists. GES has been in business since 1991 and has aeration system installations from
coast to coast in the US. Therefore we have quite a bit of experience in aeration/mixing of lakes and reservoirs.
I appreciate the opportunity to comment on the current B.E. Jordan Lake EA and to expose everyone to at least
one alternative to the "chosen" solution. Here is my list of comments:
1. It is stated in the EA that DO is not really an issue and that readings are generally above the minimum limit
of 5 mg /1, yet it is mentioned that it is possibly anoxic in the lower hypolimnion. Therefore I am not sure at
what depth the DO readings are taken as shown in the charts. The fact that the EA states that the solar units will
be adjusted such that they are avoiding circulation of any anoxic water at the bottom of the hypolimnion doesn't
sound like a good practice at all. Our perforated line diffuser systems consist of a compressor or compressors
sitting on land with a few very heavy duty, industrial strength HDPE pipes that are perforated only on the top
side and extend from hundreds to thousands of feet along the lake bottom in order to cover the area to be mixed.
The pipes are not lying on the bottom, but float at a fixed distance above the bottom as they aerate the lake.
Over the years we have found that the goal for shallower lakes, such as Lake Jordan, should be to destratify the
water column starting as close to the bottom as possible but not close enough to stir up the sediment. Our
diffuser lines follow the contour of the bottom of the lake. That way, we are not avoiding any anoxic water at
the bottom. Leaving anoxic water is a risk and when ambient temperatures drop in the Fall, that anoxic water
can get mixed all of a sudden and cause obvious issues that can last several days to clear up. It is better to have
a system that destratifies the entire water column from the beginning (installed and started -up well prior to
summertime) and then keeps it destratitied/mixed throughout the warmer season. To purposefully leave the
water stratified/anoxic below the thermocline as a normal mixing practice in the climate we live in will cause
problems at some point. We do not advise that.
2. According to the EA, there seems to be a lot of safety hazards with floating units, caused by the units
themselves being on top of the water, not very visible from a distance by approaching boaters, having many
tethers that in many cases cause a fairly large area that boaters can't approach, many buoys, lighting on the units
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that could go out, the possibility high water levels and waves can displace the units from their intended
positions, etc. A bottom diffuser type aeration /mixer system doesn't have any of those issues. Go to our web
site at www.airation.com to see on our home page what is on top of the water at lakes where our systems are
installed. You see nothing but regularly spaced small plumes / ripples on the surface of the water (if not windy)
that are caused by the air diffusers that are located near the bottom. Nothing that has to be protected by buoys,
signs, strobe lights, etc.
Our lines are not going to be hit by any boats or other recreational craft and storm winds or waves don't displace
our lines. If they did, they would cause no hazards since they would still be down just above the bottom. If the
lines have to be moved for any reason, it takes just a few turns of some valves back at the compressor location
to cause any one to rise to the top. This simple method of raising the lines also allows cleaning once a year
during a time when there is no boat traffic. Then just by turning a few valves the line submerges to its position
floating just above the bottom of the lake, and it goes back to mixing the water again. Our air lines are no
problem for those fishing and we don't find lines damaged by lures nor anchors. As a matter of fact, the fishing
has proven to be quite good near the diffuser lines and fish have a larger environment in which to live since
bottom water is no longer anoxic.
3. The EA states that "the units would be inspected for proper operation and any necessary maintenance
performed on a routine basis (at least weekly)." That is a lot of labor and time (i.e. maintenance expense)
involved, not only for the initial 36 units, but if it is decided to go ahead and install the 155 or so units that were
mentioned in the News & Observer at the end of the 2 year demonstration period, that would really be a lot of
maintenance /operating expense. The lake certainly would look like a Christmas tree from the sky, with all the
safety lights on that many units glowing. Those as well would have to be maintained. I'm sure the boaters will
enjoy navigating the obstacle course of units as well. That's a big risk/liability both in the event someone did
get hurt/killed when they hit one of the units as well as the cost to replace a unit.
I would hope that the revenue from the high attendance (970,000 people in 2010 per the EA) to the lake that is
cited in the EA would remain as high given the decreased navigability of the lake with that many or more
floating units installed in the future. If not, the decreased tourist revenue should be taken into consideration in
this decision. Other than the once /year at most (usually every few years) raising and possibly cleaning of the
lines as mentioned above, the compressor /s themselves would require normal air compressor maintenance and
there would be very few of them.
4. The EA states: "With the exception of Robeson Creek, the circulators would not be placed in the main
channel; should one exist. The circulators would present a navigational impediment similar to that of floating
markers which already exist in some areas of Jordan Lake." This is not the proper method to aerate a body of
water. With our underwater diffuser pipes, our goal is to try to install them in the deepest trenches (again near
the bottom to be sure we are mixing the deepest portions possible). Systems installed at the surface impede boat
navigation.
5. Given that the DO data seems to be acceptable (again, it isn't explained what the DO levels are throughout
the water column), the value of the chosen solution would most likely be the decrease in blue algae and
increased DO levels. I am just not sure the chrolophyll levels will be improved with the chosen units. I guess
that is why you call it a demonstration project.
The fear I have is that not only is the "demonstration project" very, very costly, it is possible it could not only be
decided to not remove the 36 demonstration units at the end of the two year period, but the installation could be
expanded to at least 155 units per the articles in the News & Observer. The EA acknowledges that by taking the
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alternative "no action ", the conditions in the lake should improve anyway. I have no doubt that some
improvement would be made with the demonstration project in the area of the installation. Our system would
provide much improvement as well.
The trouble is that Jordan Lake is very large and these two installations would most likely only improve those
specific areas as stated in the EA. The only way to improve a larger portion of the lake would be to add many
more units as they could possibly do if the demonstration was considered successful, rightfully or not, due to the
chosen solution. The thing we need to keep in mind is do we really want as many things floating on the lake as
what it would take to do the job beyond the size of the demonstration project?
6. Our vote would be to take the "No Action" alternative at this point given the two alternatives and take a
chance on seeing how well things improve without using the chosen solution, given the many issues I feel the
chosen solutions has. The EA states: "With the no action alternative, it is likely that water quality concerns in
Jordan Lake would gradually improve because the TMDL would remain in place." And that "Water quality is
expected to improve under the no action alternative, although it is difficult to determine how long it may take to
reach water quality goals.
7. The most obvious observation after reading the EA as well as the many articles in the News & Observer over
the past several months is that somehow, without competitive bidding nor discussions with vendors of
alternative aeration / mixer systems, a decision was made to narrow the solution to not only just a few floating
solutions, but even a specific one.
As the EA states, "Due to stipulations outlined in Session Law 2013 - 360 §14.3A.(a), consideration of
installation feasibility, and likely product efficacy, solar powered in -lake long- distance circulators have been
selected as the preferred action for this demonstration project. ".
In the EA, a MEMORANDUM dated 16 September 2013 from Shari L. Bryant, North Carolina Wildlife
Resources Commission Piedmont Region Coordinator, Habitat Conservation Program, with Subject: "Scoping
for Mechanical Aeration System for the Management of Nutrients in Jordan Lake, Chatham County. DENR
Project No. 14- 0069 ", Shari states: "We are concerned about direct impacts of the aeration system on aquatic
resources and recreational boating. The EA should include an alternatives analysis that evaluates other
alternatives (e.g., bottom diffuser) to the proposed surface aeration system, and includes a discussion of
environmental impacts from construction, operation, and maintenance of the proposed aeration system as well
as the other alternatives."
No evidence is shown in the EA that Shari's request to have bottom diffuser type systems evaluated has taken
place. We are a major provider of such systems. Shari is right on target with her ignored request. Bottom
diffuser type systems overcome many of the negative issues that the chosen solution has.
Lyn Hardison, NCDENR, in her review of the proposal dated September 27, 2013 points out Shari's request as
well for alternative proposals.
8. The EA states: "The Jordan Lake Reservoir has historically been one of the most eutrophic reservoirs in
North Carolina (NCDENR, 2007)." Another place where an aeration system like ours can really improve water
quality is if it is installed a good distance from the intake, with our pipes fanning out for several thousand feet
into the main body of water. Water withdrawn from the lake at the intake will then be properly aerated and
destratified before entering the intake. We are confident that our system would have a positive impact on the
water quality issues and leave no safety concerns for boaters. Any maintenance to the in -lake portion of our
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systems would be done on at most an annual basis, and when there is either no boating, or only policed boating
in the section of lake requiring maintenance. The benefits include operational and treatment costs as well as
addressing the common raw water quality problems related to manganese, iron and phosphorus concentrations
and algae related taste and odor.
If you would like to contact professionals familiar with our systems, Bill Frazier, with the City of High Point,
NC handles both City Lake and Oak Hollow Lake that are shown on our web site home page. Bill can be
reached at 336- 883 -3415 or bill.frazier @highpointnc.gov. Also, Ken Wagner, CLM, Ph.D. with Water
Resource Services Inc., is a well -known and respected professional in the water quality industry and is very
familiar with many of our installations nationwide. Ken can be reached at 413 - 219 -8071 or
[e-mail].
The mission of GES is to produce aeration/mixing solutions for water quality issues in lakes and reservoirs
caused by low dissolved oxygen content in the bottom waters and temperature stratification of the water
column.
Thanks again for the opportunity to comment on this project. Let us know if you have any questions. We look
forward to hearing from you soon.
Please contact us if you have any questions.
Sincerely,
Bill Wentzel, P.E. and VP Sales & Marketing
General Environmental Systems, Inc.
cc: Leo Wentzel - President GES
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