Swine Manure Solids Earthen Settling Basin Design
Prepared by:
James C. Barker
Professor and Extension Specialist
Biological and Agricultural Engineering
North Carolina State University, Raleigh, NC
Published by: North Carolina Cooperative Extension
Service
Publication Number: EBAE 184-93
Last Electronic Revision: March 1996 (JWM)
An earthen gravity
settling basin can remove
50% or more of the solids
from liquid swine manure
while providing solids
storage for up to 12
months between cleanouts.
The basin top width should
be no more than 100 feet
with a length-to-width
ratio near 3:1 and a
liquid depth of 8-10 feet.
The basin contents should
be thoroughly agitated and
removed for land spreading
either by liquid manure
spreader or slurry
irrigation. The following
design example for North
Carolina conditions
assumes an earthen gravity
manure settling basin more
than 1000 feet from the
nearest residence for 6
months solids
accumulation; followed by
an anaerobic treatment
lagoon and 6 months
storage of urine, excess
water usage and lagoon
surface rainfall surplus.
It does not include
storage for freeboard, a
25-year storm, or fresh
water used for pit
flushing or recharge.
Settling Basin:
0.55 gal/135 lb hog/day x 183 days = 100 gals /135 lb hog
/7.48 gals/ft3 = 13.4 ft3 /135 lb hog
/135 lb hog = 0.10 ft3/lb hog
Anaerobic Treatment Lagoon:(50% VS reduction in settling basin)
design treatment vol: 0.5 x 1.0 ft3/lb hog = 0.50 ft3/lb hog
sludge storage: 0.5 x 0.5 ft3/lb hog = 0.25 ft3/lb hog
temporary storage: 0.5 ft3 - 0.10 ft3 = 0.40 ft3/lb hog
(183-day liquid storage minus settled solids)
____________________
total volume: = 1.15 ft3/lb hog
Distributed in furtherance of the Acts of Congress of May 8 and June 30,
1914. Employment and program opportunities are offered to all people
regardless of race, color, national origin, sex, age, or disability. North
Carolina State University, North Carolina A&T State University, U.S.
Department of Agriculture, and local governments cooperating.
EBAE 184-93
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