	UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

	WASHINGTON, D.C.  20460

	

					

October 9, 2007

MEMORANDUM

SUBJECT:	Estimated Environmental Concentrations for Copper 8-Quinolinate
(Cu8Q) from a treated wood used to build docks

	From:		Siroos Mostaghimi, Ph.D., Senior Scientist

	Risk Assessment and Science Support Branch (RASSB)

	Antimicrobials Division (7510P)

	To:		Norm Cook, Chief

	Risk Assessment and Science Support Branch (RASSB)

				Antimicrobials Division (7510P) 	 

  SEQ CHAPTER \h \r 1 Attached please find the calculated Estimated
Environmental Concentrations (EECs) for Copper 8-Quinolinate treated
wood used to build docks.  

Background

	  SEQ CHAPTER \h \r 1 RASSB has decided to calculate the leaching of
Cu-8-Quinolinate (Cu8Q) from a dock into water.  It is assumed that 4%
of the total applied Cu8Q will leach from wood to water. The calculated
Estimated Environmental Concentration (EEC) will be used for the
ecological risk assessment of Cu8Q.  

The following assumptions were used for these calculations:

Dock Dimensions:

Length = 30 meters

Width = 10 meters

Thickness of the wood = 0.1 meter

       The number of poles used underneath of the dock will be 18
because it is assumed that the dock is going to be used for loading and
unloading of heavy equipments.  

The dimensions of the poles are:

Length = 2 meters

Width = 0.15 meters

Height = 0.15 meters

 The poles will be inserted into sediment by 0.5 meters.

Calculations of surface area of wood used for building the dock:

Poles area= (1.5 m x 0.15 m x 4 sides) x 18 poles = 16.2 m2

The surface of the dock = 30 m x10 m = 300 m2

 Total surface area = 300 + 16.2= 316.2 m2 = 3162000 cm2

Estimated Environmental Concentrations (EECs) Calculations:

The retention rate reported for the wood = 22 µg/cm2 , (USEPA 2006) and
we assumed a leaching rate of  4%.

22 µg /cm2 = 222000 µg /m2 = 222 mg/m2 = 0.222 g/ m2 – 0.000222
kg/m2

Then:

316 2000 cm2 X 22 µg /cm2 x 0.04 = 2782560 µg = 2782.560 mg of Copper
-8-Quinolinate

	It is assumed that the water body close to the dock contains between 6
acre feet (7400891 liters) to 24 acre foot (29603736 liters) of water. 
Using the following relationship the amount of Cu8Q in water will be:

(2782.560 mg of Cu8Q / 7400891 = 0.00038 mg/L =0.00038 ppm of Cu8Q in
water = 0.38 ppb of Cu8Q in water.  The Cu8Q concentrations in different
size water bodies are shown in Table 1:

Table 1 .Concentration of Copper 8 Quinolinolate (ppm and ppb) in
different volumes of water.

Water Body Size	Volume    Liters	Cu8Q in Water (ppm)	Cu8Q In  Water
(ppb)

1 Acre Foot	1233481.85	0.00226	2.26

6 Acre foot	7400891.13	0.00038	0.38

12 Acre foot	14801782.26	0.00019	0.19

18 Acre foot	22202673.4	0.00013	0.13

24 Acre foot	29603564.53	0.00009	0.09



Uncertainties and Limitations

Environmental conditions such as temperature, rainfall and pH, may
affect the amount of leaching of the chemical from wood.

The size and other specifications of the dock used for these
calculations may not be representative of all docks which are built in
water bodies. It is assumed that the dock will be used for boating,
loading and unloading of boating equipment, etc.

The chemical and biological reactions which usually take place under
regular environmental conditions are not considered in calculations for
this report.  Therefore, the results may not be a true representative of
what happens to this chemical under natural environmental conditions. 

References

  HYPERLINK "http://www.onlineconversion.com/volume.htm" 
http://www.onlineconversion.com/volume.htm 

	USEPA.  2006. Environmental Fate Transport Assessment for
Copper-8-Quinolinolate. 		Najm Shamim. Antimicrobials Division. 

File: 	C:\MyFiles\2007 Reports\ Cu-Naphthenate\ Estimated Environmental 
Concentrations for Cu8Q leached from a Dock into water.

	CC: Siroos Mostaghimi, RASSB

                    RASSB Chemical Files	

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