Current through Register Vol. 30, No. 38, September 20, 2024
A. A 4.21 General
Permit allows for surface application of treated wastewater that is nominally
free of coliform bacteria produced by the treatment works of an on-site
wastewater treatment facility.
B.
Performance. An applicant shall ensure that the treated waste-water distributed
for surface application meets the following criteria:
1. TSS of 30 milligrams per liter, 30-day
arithmetic mean;
2.
BOD5 of 30 milligrams per liter, 30-day arithmetic
mean;
3. Total nitrogen (as
nitrogen) of 53 milligrams per liter, five-month arithmetic mean;
4. Is nominally free of total coliform
bacteria as indicated by a total coliform level of Log10
0 colony forming units per 100 milliliters, 95th percentile.
C. Restrictions. The applicant
shall not install the disposal works if weather records indicate that:
1. Average minimum temperature in any month
is 20°F or less, or
2. Over 1/3
of the average annual precipitation falls in a 30-day period.
D. Design requirements. An
applicant shall ensure that:
1. The land
surface application rate does not exceed the lowest application rate as
determined under
R18-9-A312(D)
minus no greater than 50 percent of the evapotranspiration that may occur
during the month with the least evapotranspiration in any soil zone within the
top 5 feet of soil;
2. The design
incorporates sprinklers, bubbler heads, or other dispersal components that
optimize wastewater loading rates and prevent ponding on the land
surface;
3. The design specifies
containment berms:
a. Compacted to a minimum
of 95 percent Proctor;
b. Designed
to contain the runoff of the 10-year, 24-hour storm event in addition to the
daily design flow; and c. Designed to remain intact in the event of a more
severe rainfall event; and
4. The design incorporates placement of
signage on hose bibs, human ingress points to the surface disposal area, and at
intervals around the perimeter of the surface disposal area to provide
notification of use of treated waste-water and a warning against
ingestion.
E.
Installation requirements. An applicant shall ensure that installation of the
wastewater dispersal components conforms to manufacturer's specifications that
do not conflict with this Article and to the design documents specified in the
Construction Authorization issued under
R18-9-A301(D)(1)(c).
F. Operation and maintenance. In addition to
the requirements specified in
R18-9-A313(B),
the permittee shall operate and maintain the surface disposal works to:
1. Prevent treated wastewater from coming
into contact with drinking fountains, water coolers, or eating areas;
2. Contain all treated wastewater within the
bermed area; and
3. Ensure that
hose bibs discharging treated wastewater are secured to prevent use by the
public.
