Dr Ken Ashley
BC Ministry of Environment Fisheries Branch

Hypolimnetic Aeration Project Sheldrake Lake Nova Scotia

Ken

Finally got the funds together to proceed with our pilot Hypolimnetic
Aeration Project and would like to move ahead and contract your services as
Technical Advisor as previously discussed. From our previous correspondence
I recollect you suggested about a week of your time would be required at
standard consulting rates and we have set aside up to $3000 for that
purpose.

I hope you still have the Brief on Sheldrake Lake written by Shalom
Mandeville dated 17 May 1994 which inspired our project and forms the basis
for our efforts to todate. (We still hope to persuade Shalom to become
involved in the implementation of the project he initiated but he is heavily
committed to local and international projects at this time. We will keep
trying.)

Referring again to your e-mail, I note that you were careful to qualify your
opinion that hypolimnetic aeration appears as a suitable restoration for
this lake procedure with the observation that  because of certain anomalies,
special design precautions might be necessary to maintain stratification
during summer. We particularly need your expert advice in this regard. We
have recently sounded the Lake and confirmed the maximum depth as 22 feet.

Typically, our funding has various strings attached including the need to
press ahead and commence operations this summer to conform to the budgeting
schedules of our sponsors.

The equipment we are purchasing is being purchased from  Mark One Air
Equipment Limited and consists of

1 model Pro4 Oxygen Generator. Oxygen output flow of 32 SCFH. Output
pressure of 45-50 PSIG.  Output purity of 94%, +/-2%. Dimensions of 26" x
26" x 82", weight of 300 Lbs.


1  hydrovane  compressor model RU-S, rotary vane air compressor. This is
a modulating type compressor that is designed to operate 24 hours per day,
all year. Power is 575/3/60 or 220/3/60.


I Wilkerson model. MI6-04-FOO, 11/2" NPT coalescing filter, c/w auto drain.


1 reel of 1/2" hose, PVC braided. P/N PVC-128-500. Length is 500 feet.


1 assortment of fittings, 2 ball valves and a pressure switch to
indicate if no oxygen is flowing, Includes a discharge regulator.


1 Diffuser manifold with 1/2" NPT inlet and 4 x 1/2" diffuser tubes,
and back flow check

As the situation now stands we have ordered the compressor and separator and
are working at construction of a small shed on a concrete pad near the lake
and arrangements for power supplies. However we need you advice particularly
with respect to the diffusers, regulation of release, and any other advice
you may have to offer.

We have initiated an intensive water sampling program and plan for a
complementary biological sampling program but need direction on what samples
to take, sampling protocols and where to get them analyzed. We have asked a
Dalhousie faculty member for advice but would like any recommendations you
may have to offer. l

Since the Nova Scotia Ministry of the Environment is a major sponsor of the
pilot project it is hoped  that your technique will be applied in other
shallow lakes thoughout the province depending on results of the pilot
project. In this regard any public relations material you may have would
also be appreciated so we can get the attributions right.

Yours aye Frank Hope