[Code of Federal Regulations]

[Title 40, Volume 24]

[Revised as of July 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 40CFR227.29]



[Page 215-216]

 

                   TITLE 40--PROTECTION OF ENVIRONMENT

 

         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)

 

PART 227_CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN 

DUMPING OF MATERIALS--Table of Contents

 

                          Subpart G_Definitions

 

Sec.  227.29  Initial mixing.



    (a) Initial mixing is defined to be that dispersion or diffusion of 

liquid, suspended particulate, and solid phases of a waste which occurs 

within four hours after dumping. The limiting permissible concentration 

shall not be exceeded beyond the boundaries of the disposal site during 

initial mixing, and shall not be exceeded at any point in the marine 

environment after initial mixing. The maximum concentration of the 

liquid, suspended particulate, and solid phases of a dumped material 

after initial mixing shall be estimated by one of these methods, in 

order of preference:

    (1) When field data on the proposed dumping are adequate to predict 

initial dispersion and diffusion of the waste, these shall be used, if 

necessary, in



[[Page 216]]



conjunction with an appropriate mathematical model acceptable to EPA or 

the District Engineer, as appropriate.

    (2) When field data on the dispersion and diffusion of a waste of 

characteristics similar to that proposed for discharge are available, 

these shall be used in conjunction with an appropriate mathematical 

model acceptable to EPA or the District Engineer, as appropriate.

    (3) When no field data are available, theoretical oceanic turbulent 

diffusion relationships may be applied to known characteristics of the 

waste and the disposal site.

    (b) When no other means of estimation are feasible.

    (1) The liquid and suspended particulate phases of the dumped waste 

may be assumed to be evenly distributed after four hours over a column 

of water bounded on the surface by the release zone and extending to the 

ocean floor, thermocline, or halocline if one exists, or to a depth of 

20 meters, whichever is shallower, and

    (2) The solid phase of a dumped waste may be assumed to settle 

rapidly to the ocean bottom and to be distributed evenly over the ocean 

bottom in an area equal to that of the release zone as defined in Sec.  

227.28.

    (c) When there is reasonable scientific evidence to demonstrate that 

other methods of estimating a reasonable allowance for initial mixing 

are appropriate for a specific material, such methods may be used with 

the concurrence of EPA after appropriate scientific review.