Municipal Separate Storm Sewer System (MS4) permit requirements
were implemented in two phases: Phase I for large
and medium MS4s and Phase II for regulated small
MS4s.
Phase I MS4 Requirements
If you operate an MS4 which serves or is located in an
incorporated place or county with a population of 100,000 or
greater (based on the 1990 U.S. Census), then you operate a
regulated Phase I MS4 and you must
apply for a renewal permit*.
*Please note that all Phase I MS4s are already permitted and
there are no new Phase I designations.
Phase II MS4 Requirements
If you operate a small MS4
-
located in an urbanized area
(UA), as defined by the Bureau of the Census
-
or located outside of a UA and are brought into the program on a
case-by-case basis by the Texas Commission on Environmental Quality
(TCEQ),
Then you operate a regulated small MS4 and must obtain
authorization.
To determine if you are located in a UA you can visit the
Environmental Protection Agency's (EPA's) Urbanized Area Map Results
for Texas web
page and use the Storm
Water Permit Area Locator Viewer.
Contact us if
you have any questions about this general permit.
