clarification of the proposed elg request for comments (item a.2, p 182) alternative groundwater...
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Clarification of the Clarification of the Proposed ELGProposed ELG
Request for comments (Item A.2, p 182)Request for comments (Item A.2, p 182)
Alternative Groundwater Alternative Groundwater AssessmentsAssessments
Groundwater and Groundwater and surface water are not surface water are not separate resourcesseparate resources
The land application of The land application of domestic sewage, domestic sewage,
manure and manure manure and manure derived products is an derived products is an
established established conservation practiceconservation practice
Example:Example:Septic tank disposal fields Septic tank disposal fields and supplemental cropland and supplemental cropland fertilization are considered fertilization are considered
acceptableacceptable
An Infiltration rate of An Infiltration rate of 1010-7 -7 cm/sec from liquid cm/sec from liquid
manure storages is manure storages is equivalent to equivalent to
approximately 3.15 cm approximately 3.15 cm per yearper year
Assuming ammonia concentration of Assuming ammonia concentration of 500 mg/l in this infiltrating water, no 500 mg/l in this infiltrating water, no denitrification losses, this is denitrification losses, this is equivalent to a nitrogen application equivalent to a nitrogen application rate of 150 kg/ha. This is about 25% rate of 150 kg/ha. This is about 25% more than the contribution of two more than the contribution of two household septic tank systems per household septic tank systems per acre.acre.
We are aware of no evidence We are aware of no evidence that lagoons or manure that lagoons or manure
storage basins meeting this storage basins meeting this infiltration criteria are infiltration criteria are
contributing to groundwater contributing to groundwater pollution.pollution.
The environmental cost The environmental cost of specifying an of specifying an
impermeable liner for all impermeable liner for all manure storages and manure storages and
lagoons is greater than lagoons is greater than the benefitsthe benefits
Liners fail with a Liners fail with a sufficient frequency to sufficient frequency to
obviate possible benefitsobviate possible benefits
Liners can and will Liners can and will continue to be used in continue to be used in
those locations in which those locations in which the infiltration criteria the infiltration criteria
can not be met with local can not be met with local resourcesresources
Seepage from lagoons Seepage from lagoons and storage basins and storage basins
meeting the infiltration meeting the infiltration criteria is insignificant criteria is insignificant compared to the land compared to the land
application component application component of the systemof the system
Monitoring wells installed Monitoring wells installed around lagoons and other around lagoons and other manure storage basins are manure storage basins are insensitive tools by which to insensitive tools by which to
monitor groundwater monitor groundwater contamination.contamination.
Accurate measurement of Accurate measurement of downward movement on downward movement on nitrogen bearing leakage nitrogen bearing leakage
requires use of a permeable requires use of a permeable wick sampler which is a wick sampler which is a
research tool and not adapted research tool and not adapted to routine monitoringto routine monitoring
ConclusionConclusion
The requirement of a The requirement of a synthetic impermeable synthetic impermeable
liner in all anaerobic liner in all anaerobic lagoons and earthen lagoons and earthen
storage basins is storage basins is inappropriate.inappropriate.
Other important Other important considerations considerations
How do we deal with How do we deal with existing facilities that can existing facilities that can
not assure infiltration not assure infiltration rates less than the rates less than the
criteria?criteria?
Alternate and evolving Alternate and evolving technologies have the potential technologies have the potential to claim marketable by-products to claim marketable by-products sufficiently valuable to support sufficiently valuable to support
inter basin sales.inter basin sales.
Extreme rainfall conditions Extreme rainfall conditions are an infrequent cause of are an infrequent cause of
water quality damage water quality damage based on the U.S. based on the U.S.
university representatives to university representatives to the National Center the National Center
RoundtableRoundtable
Conclusion IIConclusion II
The establishment of a The establishment of a discharge criteria more discharge criteria more restrictive than the 25 year - restrictive than the 25 year - 24 hour storm event will 24 hour storm event will contribute significant contribute significant additional cost but gain little additional cost but gain little water quality improvement. water quality improvement.
New technologies promise New technologies promise future benefitsfuture benefits
Alternating anaerobic - aerobic Alternating anaerobic - aerobic digestion units are producing digestion units are producing discharge quality effluent.discharge quality effluent.
Anaerobic digesters are being built Anaerobic digesters are being built for economically driven biogas for economically driven biogas production.production.
Nutritional advances allow designing Nutritional advances allow designing better manure.better manure.
New technologies promise New technologies promise future benefitsfuture benefits
Permeable covers that provide Permeable covers that provide odor control, reduced ammonia odor control, reduced ammonia evolution are evolving toward evolution are evolving toward methane removal.methane removal.
Special concerns of cow-calf Special concerns of cow-calf operatorsoperators
Cow and calf operate as a single unitCow and calf operate as a single unit Feeding on vegetated fields is a non-Feeding on vegetated fields is a non-
point source and should not be point source and should not be permitted as a point sourcepermitted as a point source
It is important that the definition of a It is important that the definition of a CAFO retain the lack of a ground CAFO retain the lack of a ground
cover as part of the necessary cover as part of the necessary definition, otherwise, many of the definition, otherwise, many of the western range operations will be western range operations will be
moved toward the permitting moved toward the permitting process with no pollution process with no pollution
prevention benefits.prevention benefits.
Co-permitting concernsCo-permitting concerns
Co-permitting would seem Co-permitting would seem reasonable in situations where the reasonable in situations where the animals are owned by a single or animals are owned by a single or small number of owners beyond the small number of owners beyond the facility owner. It does not work in the facility owner. It does not work in the case of western feedlot operations case of western feedlot operations where there may be many owners of where there may be many owners of cattle in a custom feedlot cattle in a custom feedlot
As Land Grant University faculty As Land Grant University faculty involved in research and involved in research and extension activities, we extension activities, we
appreciate this opportunity to appreciate this opportunity to share our thoughts with you, our share our thoughts with you, our
agency colleagues.agency colleagues.