[Coral-List] Reference to address necessary measures to minimize environmental impact of a desalination plant

[Ivan Steward]

To add to what Dennis has mentioned, with regard to ensuring that effluent
is ideally discharged below the thermocline - is the need to (ideally)
assess the likelihood of any regional upwelling that may push cooler waters
(and consequently the effluent) back toward the surface layer. So, at least
a cursory understanding of the relevant oceanographic context is probably
advisable.

I have a fair degree of experience working on projects involving deep sea
tailings placement (which involves siting pipelines at ~200m depths), and
assessing the ecological effects thereof.

If I can assist further please feel free to get in touch.

Regards,
Ivan

On Sat, 12 Sep 2020, 06:00 Dennis Hubbard via Coral-List, <
coral-list at coral.aoml.noaa.gov> wrote:

> Hi Valerie:
>
> Fortunately, this is not a new topic and I THINK that the main issues are
> well delineated. The first is more clear-cut but technically more
> difficult. It is critical that the effluent be released below the ocean
> thermocline (ideally 300m but probably more practically 100 meters). The
> second is to use measures to eliminate or significantly reduce physical
> damage during installation. Surveys to reduce the physical contact with
> corals and other locally important species (i.e., those that have less
> ability to return quickly) can be very valuable in siting the pipeline
> corridor. While some have argued that carefully placing effluent pipes is a
> simple matter, I would argue that the post-project damage assessments I
> have read suggest that either this is not the case or the folks doing the
> installations were complete imbeciles.
>
> It has also been my experience that engineers and "planners" place a higher
> premium on economics and aesthetics above water than on avoiding damage
> offshore. A critical decision will be based on the likely damage potential
> related to floating a pre-assembled pipe to the shelf edge versus having
> divers assemble the pipeline section by section. One the one hand, it is
> VERY tricky to lower a long pipeline into even a broad corridor without
> landing on corals and other sensitive organisms (including divers). On the
> other hand, "death by a thousand cuts" may be the outcome of divers
> lowering and assembling individual lengths of pipe.
>
> One other consideration -  marine scientists that are well educated in
> ecological dynamics are often poorly versed in the practicalities of marine
> construction. As a result, ecology and economy are too often in conflict
> and we all know who the winner will be. So, it is VERY important to
> identify the technical folks who appreciate the value of the marine
> community but also know the intricacies of working with heavy equipment in
> the shallow marine environment. It has been my experience that working with
> colleagues who have backgrounds in the professional diving community (and
> here I'm talking "oil field "grunts" and the like - not dive instructors).
> I had years of experience working with this community during my tenure as
> Science Coordinator of Hydrolab on St. Croix - and I often found that they
> worried as much about the reefs as I did... and sometimes they were even
> more restrictive than I argued for. If you want recommendations, let me
> know; many of my professional-diving collaborators are on St. Croix and can
> be trusted. I'd be happy to make a trip for pre-assessment if needed, but
> they would be cheaper as they are closer.
>
> Best,
>
> Dennis
>
> On Wed, Sep 9, 2020 at 7:51 AM Valerie Gregoire via Coral-List <
> coral-list at coral.aoml.noaa.gov> wrote:
>
> > Good Day Dear Coral-Listers,
> >
> > I have a colleague, who is not on the list, that is working on a proposal
> > for EIA report for a desalination plant in St.Kitts, Caribbean. In order
> to
> > address the necessary measures to minimize the environmental impact of
> the
> > desalination plant with the bine disposal as well as with the routing and
> > placement of pipe, She is looking into guidelines, internationale
> standard.
> > If anyone ever work into a desalination project and have some useful
> > reference, please contact me. Thank you very much.
> >
> > Warms regards,
> > Valerie Gregoire M.Sc.Marine Biology
> > Tel: +1869-660-9415
> > Email: vg.valeriegregoire at gmail.com
> >
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> >
>
>
> --
> Dennis Hubbard - Emeritus Professor: Dept of Geology-Oberlin College
> Oberlin OH 44074
> (440) 935-4014
>
> * "When you get on the wrong train.... every stop is the wrong stop"*
>  Benjamin Stein: "*Ludes, A Ballad of the Drug and the Dream*"
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