Development of a Negative Air Pressure Cover System for Swine Manure Earthen Storages in Manitoba

Project: MLMMI 98-01-32


To demonstrate the effectiveness of a Negative Air Pressure Cover System for Swine Manure Earthen Storages in Manitoba under the climatic conditions of all seasons.


Doug Small,
DGH Engineering Ltd.


Status: Completed
Started: 1998-09-21
Completed: 1999-11-25

Funding Partners: who have contributed to MLMMI in support of this project:
HEMS - $26,500
Triple S - $17,000
Manitoba Pork Council and industry groups - $9,500

Amount Funded: $53,000.00
Performer Funded: $0.00
Total Cost: $53,000.00


Final Report due Oct. 30, 1999; received November 25/99.
Further Development: DGH has applied for a patent and has made the decision to go into full commercialization. They have installed the covers on some lagoons and expect to more.
In July 2000, DGH formed the company 'Encon Technologies' to market the covers.


Most livestock manure in Canada is retained in storage until it can be applied to agricultural lands to be used as a resource for crop production and soil improvement. Earthen manure storages are an economically attractive alternative for manure management that gives a competitive advantage to livestock producers.

Because of their large surface area, earthen manure storages are the focus of concerns regarding odours from hog operations. This project was intended to demonstrate and evaluate a cover system that will help to improve the economic and environmental performance of earthen manure storages.

The novel cover system proved to have many advantages including:

  • Year round control of odour from the manure storage basin
  • Cost-effectiveness
  • Increase in the fertilizer value of manure due to the reduction in ammonia volatilization
  • Elimination of a breeding habitat for flies
  • Prevention of precipitation entering the storage basins
  • Ease of installation
  • Reliability, durability and stability

The use of a negative air pressure cover system will provide livestock producers with a single, inexpensive method to eliminate odour, the most prominent problem, associated with manure storages. It will also enhance the value of manure as a nutrient source for crop production.


Full Report

Manitoba Pork represents 614 Manitoba hog farms