Oct 22

There are three types of constructed wetlands:
1.  Restored wetlands - those under rehabilitation.
2.  Constructed wetlands - built where none existed before (usually for
water treatment).
3.  Created wetlands - those that are wildlife oriented.

1.  Water treatment - this may include wastewater, acid mine drainage,
highway runoff,  
      specific pollutants, or stormwater.
2.  Hydraulic modification - for flood control, water storage, or
groundwater recharge.
3.  Water quality changes - for the removal of sediment, change of pH, or
to add or remove 
      organics (remove in the case of paper mills, add in acid mine
drainage). 
4.  Erosion protection - bank or shoreline stabilization, or to alter flow
patterns.
5.  Open spaces and aesthetics - used by resorts or new developments.
6.  Mitigation - intended to replace the function of lost wetlands.
7.  Life support as a habitat - a place for endangered species.

For information and data concerning wetland systems in use, search the EPA
Wetlands Treatment Database.

Oct 24

Building a constructed wetland:

I.  Design
	Free water systems
	Subsurface systems
Concerns include the input water quality, pretreatment, groundwater
protection, size (suggested 150 m2 / kg BOD), regulations, and the use of
parallel cells in case of problems.

II.  Soils
It is important to check for permeability, bulk density and liquid limit.
(How fast will the water percolate?  What will be retained?)
Also check depth to the water table.
Usually the top soil is removed and then replaced after construction for
use as a growing medium.
Loam soil is often the soil of choice because it provides a better support
than sand and has more room for root growth than regular soil.
Most soils used have a pH between 6.5-8.5 and CEC > 15 meq/100g.
The soil used may be cultivated for direct seeding.

III.  Construction
1.  Have drawings checked (NRCS or county ag. agent).
2.  Clear, stake, and take care of grading.
3.  Place seepage control layer (clay or plastic liner).
4.  Select and place soil.
5.  Water level control and conveyance (plumbing).
6.  Cultivate and presoak, then plant.



IV.  Water Management
It is important to simulate natural processes (periodic drying out,
oxidation at the bottom), control flow levels, and control residence time.

V.  Vegetation
The roots and stems are the most important plant parts.
In selecting plants it may be necessary to purchase, rear yourself, or
collect and transplant.
Most sites use indigenous plants.
Handbooks list plant suggestions for different regions and types of waste.
The Texas and Florida Aquatic Plants Guides are good databases.
Handbooks also suggest when and how to plant.

VI.  Operation and Maintenance
1.  Start up as soon as possible after planting to avoid losses.
2.  Determine seepage and evaporation to control water level.
3.  Check vegetation for any diseases or pests.
4.  Adjust water level to control pests and aerate shallow areas.

VII.  Monitoring
1.  Watch the flow rates.
2.  Check on water quality (BOD, TSS, nitrate and phosphate levels, fecal
coliforms, 
      heavy metals).
3.  Check for any groundwater leakage by sampling in nearby wells or use
of a neutron   
      probe. 

VIII.  Regulations
1.  For discharge to waters of the state you need to follow NPDES
(National Pollution 
     Discharge Elimination System) or BMP (Best Management Practices).
2.  For construction you must check with the Army Corps of Engineers.
3.  For groundwater protection check with ADEQ for an aquifer protection
permit.
4.  For reuse also check with ADEQ for a reuse permit.
5.  For the collection of plants for transplantation check with Az. Game
and Fish or the Dept. of Ag. for plant material acquisition permits.