Updates on Standards

Jennifer Zwicke

NRCS Environmental Engineer

Revision to AWMFH

• Revision to Ag Waste Management Field Handbook Appendix 10D - Design and Construction Guidelines for Waste Impoundments Lined with Clay or Amendment Treated Soil– In cases where manure sealing is occurring:

Acceptable specific discharge is changing from 1 X 10-5 cm/s (9,240 gallons per acre per day) to 5000 gallons per acre per day.

– different units for specific discharge and coefficient of permeability because terms are often confused

• gallons per acre per day for specific discharge• feet per day or centimeters per second for permeability

Revision to AWMFH (cont)• Expanded discussion on:

– importance of achieving compaction wet of optimum to achieve the lowest possible permeability in a compacted clay

– bentonite treated and soil dispersant treated liners – perimeter drains – properties of completed structure, including obtaining

undisturbed samples, performing density/water content measurements during construction, and whole lagoon seepage measurements

– concept of progressive design

Waste Treatment Lagoon 359

• Updated January 2006

• Very similar to previous (1999) version. When Appendix 10D is finalized, this practice will be affected

Solid Liquid Waste Separation 632

• Updated January 2006

• Add more specific separator efficiencies

Pond Sealing or Lining - Flexible Membrane 521A

Proposed changes to 590

• For the risk assessment (P Index) and the annual nutrient budget where there is no history of animal waste application on the unit, a soil test less than 5 years old can be used

• For the risk assessment (P Index) and the annual nutrient budget where there is a history of animal waste application on the unit, a soil test no more than 1 year old will be used.

• Time between manure test date and application date will be no more than one year

• allow rotational P205 manure application equal to recommended P or crop uptake for the crop rotation (or multiple years of the rotation) only on sites with a P Index rating of low or medium