[Code of Federal Regulations]
[Title 40, Volume 22]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR230.42]

[Page 266]
 
                   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 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.