[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: 40CFR230.42]



[Page 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 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.



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