septic.str

This file contains the septic system parameters.

Data contained in the septic.str data file are: type of septic system, geometry of biozone, characteristics of biomass, and bio-physical reaction coefficients occurring in the biozone (adapted from Siegrist et al. (2005)).

Field	Description	Type	Unit	Default	Range
name	Name of septic system record	string	n/a	n/a	n/a
typ	Septic system type	integer	n/a	0
yr	​Year the septic system became operational	integer	n/a	0
operation	​Septic system operation flag	integer	n/a	0	0-2
residents	​Number of permanent residents in the house	real	n/a	1	1.0-12.0
area	​Average area of drainfield of individual septic systems	real	m^2	1
t_fail	Time until failing systems gets fixed	integer	days	0	0-150
dp_bioz	Depth to the top of the biozone layer from the ground surface	real	mm	1
thk_bioz	Thickness of biozone layer	real	mm	1
cha_dist	Distance from septic system to the stream	real	km	2
sep_dens	Number of septic systems per square kilometer	real	n/a	2
bm_dens	Density of biomass	real	kg/m^3	1
bod_decay	BOD decay rate coefficient	real	m^3/day	2
bod_conv	Conversion factor representing the proportion of mass bacterial growth and mass BOD degraded in the septic	real	n/a	2
fc_lin	Linear coefficient for calculation of field capacity in the biozone	real	n/a	1
fc_exp	Exponential coefficient for calculation of field capacity in the biozone	real	n/a	2
fecal_delay	Fecal coliform bacteria decay rate coefficient	real	m^3/day	2
tds_conv	Conversion factor for plaque from TDS	real	n/a	2
mort	Mortality rate coefficient	real	n/a	2
resp	Respiration rate coefficient	real	n/a	3
slough1	Linear coefficient for calculating the rate of biomass sloughing	real	n/a	2
slough2	Exponential coefficient for calculating the rate of biomass sloughing	real	n/a	2
nit	Nitrification rate coefficient	real	n/a	2
denit	Denitrification rate coefficient	real	n/a	3
p_sorp	Linear P sorption distribution coefficient	real	L/kg	1
p_sorp_max	Maximum P sorption capacity	real	mg P/kg soil	1
solp_slp	Slope of the linear effluent soluble P equation	real	n/a	3
solp_int	Intercept of the linear effluent soluble P equation	real	n/a	3

References

Siegrist, R.L., J. McCray, L. Weintraub, C. Chen, J. Bagdol, P. Lemonds, S. Van Cuyk, K. Lowe, R. Goldstein, and J. Rada (2005): Quantifying Site-Scale Processes and Watershed-Scale Cumulative Effects of Decentralized Wastewater Systems. Project No. WU-HT-00-27. Prepared for the National Decentralized Water Resources Capacity Development Project, Washington University, St. Louis, MO, by the Colorado School of Mines.