On
Meeting of Toxicity ve. Copper from Cables in Enewetak
Attendees:

B.
C.
T.
F.
S.
V.
We.

W.
L.
P.
L.
V.

Wachholz
Osterberg
Jeffries
Harrison
Smith
Noshkin
L - Templeton

DOE/EV DOE/EV
DNA
LLL
U Hawaii
LLL
PNL

goon

410145

The question had been raised whether the corrosion of the cables on
the bottom of the lagoon could result in a toxicity problem to the
organisms of the lagoon. If so, DNA would have to remove the cables.
Despite all the tales of the "gold mine" of copper that was present
it was clear from the source term data presented by Jeffries that it
probably did not exceed 100 tons. The total length was about 263 miles
with only 25% of this being heavy power cable, the remainder was
telecommunication cable. Most of the cable was in a channel on the east
side of the lagoon. Noshkin, who had raised the question, showed some
examples of power cable from Runit. The outside covering did contain
some radionuclides but these were of no radiological significance. The
internal copper material was clean.
The conditions for copper toxicity were discussed.

Against ambient

levels of 0.2 - 0.6 ug/litre the available data for corals would suggest

a level of 2 ug/1 having some effect upon corals. Other organisms seem
to need 3 - 10 ug/litre to elict a response. The organism complexing
capacity of the seawater was likely to be low.

The hydrographic conditions for the cable channel are such that the
residence time for the water on the east side of the lagoon is about
once a month but near to the southeast pass could be as high as one ina
few days.
Consolidation of the facts indicated that the seawater concentration
would have to be elevated by 2 to 5 times to reach a level of 1 ppb. In

the extreme case if all the copper cable (92 tons) dissolved instaneously

with an average flushing rate of one month it is doubtful if the level
would,reach 1 - 2 ug/1. However, with a low dissolution rate, e.a., 20
mg/cm-/day, it may take decades for al] the copper to go into solution
since the insulation will fail at a varying rate, some of the cable will
be covered with growing coral and probably protected and some of the
cable may be buried in the sediments. Additionally, the cable is located
in the area of maximum flushing rate. It is also worthy of note that

this area has been subjected to source terms (i.e., copper based antifouling

paints designed to dissolve) greater than the present one, when tens of
ships anchored there during the tests.
On the basis of the available data the cables presently on the
bottom of Enewetak Lagoon do not pose any significant long term threat

to the ecological health of the lagoon, and therefore do not need to be

removed.

\Mevelih

W. L. Templeton
Associate Manager
Ecological Sciences Department

Battelle, Pacific Northwest Laboratories

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