[Code of Federal Regulations]
[Title 40, Volume 24]
[Revised as of July 1, 2005]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR230.42]

[Page 268-269]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 230_SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF DISPOSAL 
SITES FOR DREDGED OR FILL MATERIAL--Table of Contents
 
          Subpart E_Potential Impacts on Special Aquatic Sites
 
Sec. 230.42  Mud flats.

    (a) Mud flats are broad flat areas along the sea coast and in 
coastal rivers to the head of tidal influence and in inland lakes, 
ponds, and riverine systems. When mud flats are inundated, wind and wave 
action may resuspend bottom sediments. Coastal mud flats are exposed at 
extremely low tides and inundated at high tides with the water table at 
or near the surface of the substrate. The substrate of mud flats 
contains organic material and particles smaller in size than sand. They 
are either unvegetated or vegetated only by algal mats.
    (b) Possible loss of values: The discharge of dredged or fill 
material can cause changes in water circulation patterns which may 
permanently flood or

[[Page 269]]

dewater the mud flat or disrupt periodic inundation, resulting in an 
increase in the rate of erosion or accretion. Such changes can deplete 
or eliminate mud flat biota, foraging areas, and nursery areas. Changes 
in inundation patterns can affect the chemical and biological exchange 
and decomposition process occurring on the mud flat and change the 
deposition of suspended material affecting the productivity of the area. 
Changes may reduce the mud flat's capacity to dissipate storm surge 
runoff.