1. Ponds
which must discharge directly to a stream without a settling basin
should be used to culture species of sizes of fish which have minimize
the potential for causing water quality problems (e.g., fry or
fingerlings or low density culture of stockers or food fish). Many
other BMPs can be used on these ponds to reduce turbidity (e.g.,
remove most fish before onset of draining, drain last water slowly,
use of harvest basins, no draining while seining, etc.).
2. 2.
When possible, construct structures in drainage ditches/canals to
stabilize flow and allow sediment settling. Do not disturb
non-woody vegetation in open drainage structures, and where
possible, keep the bottom of the structures flooded to encourage
the growth of aquatic vegetation.
3. Written
records of pond discharges, or any activity which could disturb normal
stream flows or conditions, shall be maintained. The record should
include at least the following information: date and time of activity
or discharge, duration of activity or discharge, volume of discharge,
location of activity or discharge.
4. Aquatic
culture facilities shall maintain all the Material Safety Data Sheets
(MSDS) for drugs and/or chemicals used in the fish ponds, and shall
maintain records of all drugs and/or chemicals used in each pond.
Records shall include the amount(s) used and inclusive dates of use.
Culture pond water containing chemicals and/or drugs shall not be
discharged within the EPA-approved withdrawal period. Do not apply
chemicals at any time or in any manner which would result in a toxic
discharge.
5.
Discharge the final 12 inches (30 cm) of sediment-laden pond water to
a retention/settling basin, and allow sediments to settle for at least
24 hours before discharge
6.
Sediments removed from ponds should be used for levee repair or to
provide topsoil to denuded areas within the farm. Vegetate all exposed
sediments as soon as possible to minimize erosion and discharge.
7. Storm
water discharge from empty or dry ponds shall be settled before
release
8. When
possible, design or retrofit aquaculture farms to minimize or
eliminate discharge. Total retention facilities are not subject to
discharge regulations
9.
Discharge pipes or ditches should be constructed to avoid erosion of
pond levees, ditch embankments or beds, or stream banks or beds.
Extend drain pipes beyond toes of embankments to prevent erosion of
the embankments by discharge. If discharges have a vertical drop, the
splash area should be protected with bedrock, rip rap or concrete
10.
Construct discharge ditches/canals with adequate hydraulic cross
sections and side slopes to minimize erosion, and vegetate levee
slopes
11. The
use of concrete or metal in-pond harvest basins will eliminate pond
seining at the end of harvest operations for some species and life
stages of fish. Fish will be taken from the basin, thus not stirring
the bottom sediments. The basin will keep sediments away from the
drain
12. Divert
excess runoff from large watersheds away from the farm to minimize
input of suspended solids and nutrients to the ponds or farm storm
water discharge
13.
Vegetate pond levees and road embankments as soon as possible after
construction to prevent erosion and sediment release. Follow
recommended fertilization rates for vegetative cover to minimize risk
of nutrient discharge
14. Where
appropriate, vegetate the interior levees and pond bottoms of ponds
that are normally dried between production cycles. Close pond drains
when renovating inside earthwork to prevent discharge of suspended
solids after rains
15.
Establish grass or other vegetation on all denuded areas of farm
watershed to minimize erosion and sediment/nutrient transport
16. Do not
apply fertilizer to ponds within the last week prior to draining. If
manure from warm blooded animals is used to fertilize ponds, use
composted manure if possible, and discharge to a vegetated
retention/settling unit before discharge. Fertilize ponds only to
promote plankton blooms
17. Use
stocking and feeding practices that do not lead to serious water
quality deterioration within ponds. Minimize accumulation of uneaten
feed in ponds, and do not discharge uneaten feed
18. Use
aerators to prevent low oxygen concentrations in culture ponds, but
operate aerators to minimize erosion of pond bottoms and embankments
19. Store
fertilizers, lime, salt and other pond amendments so they are not
discharged with storm water runoff
20. When
fish are harvested with seines, or when farm workers mix or wade in
pond water when harvesting, harvest all fish possible before draining
the ponds
21. Do not
drain water while seining or wading in ponds. Avoid water discharge
during final seining. Try to do final seining during the coolest part
of the day to minimize activity levels of the fish which would
aggravate sediment resuspension
22. Flow
rates of discharged water should be managed to avoid increasing
turbidity in the receiving stream
23. Pond
drains should be operated to minimize sediment release.
Report
from The Oklahoma Aquaculture Association