| (a) All manholes must pass a leakage test.
(b) An owner shall test each manhole, after assembly
and before backfilling, for leakage using hydrostatic exfiltration
testing, vacuum testing, or any other method approved in writing by
the executive director. A manhole must be tested separately and independently
from the collection system pipes.
(1) Hydrostatic Testing.
(A) The maximum leakage rate for hydrostatic testing
or any alternative test methods is 0.025 gallons per foot diameter
per foot of manhole depth per hour.
(B) To perform a hydrostatic test, an owner shall seal
all wastewater pipes coming into the manhole with an internal pipe
plug, fill the manhole with water, and maintain the test for at least
one hour.
(C) A test for concrete manholes may use a 24-hour
wetting period before testing to allow saturation of the concrete.
(2) Vacuum Testing. An owner must perform vacuum testing
according to either subparagraph (A) or (B) of this paragraph. If
a manhole fails the vacuum test, the owner must apply grout to the
exterior of the excavated manhole before retesting the manhole.
(A) Texas Test.
(i) To perform a vacuum test, an owner shall plug all
lift holes and exterior joints with a non-shrink grout and plug all
pipes entering a manhole.
(ii) Grout may not be placed in horizontal joints before
testing.
(iii) Stub-outs, manhole boots, and pipe plugs must
be secured to prevent movement while a vacuum is drawn.
(iv) An owner shall use a minimum 60 inch/lb torque
wrench to tighten the external clamps that secure a test cover to
the top of a manhole.
(v) A test head must be placed at the inside of the
top of a cone section, and the seal must be inflated in accordance
with the manufacturer's recommendations.
(vi) There must be a vacuum of 10 inches of mercury
inside a manhole to perform a valid test.
(vii) A test does not begin until after the vacuum
pump is off.
(viii) A manhole passes the test if after 2.0 minutes
and with all valves closed, the vacuum is at least 9.0 inches of mercury.
(B) American Society for Testing and Materials (ASTM)
Test. The owner may require manhole testing that meets the requirements
of ASTM D1244-11.
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