Bill Payment Information

Si Environmental (formerly TOPS) serves as a water/ wastewater utility operator for Harris County MUD 537.

Si Environmental, LLC
Attn: Jaison Sanwald

9826 Whithorn Dr.,
Houston, TX 77095

Phone: (281) 807-9500

Pay Your Bill Online
Additional Payment Options & Service Requests

Customer Support

For billing, service requests and other inquiries use the following:

General Customer Service Number: (281) 807-9500

Customer/Billing Inquiries Email:

For general phone inquiries, please contact our Customer Service department Monday through Friday from 8:30 a.m. to 5:00 p.m., with the exception of holidays.

Customer Service/Payment Center Office
9431 Rio Grande Dr.
Houston, TX 77064

Phone: (281) 807-9500

Main Office
6420 Reading Road
Rosenberg, TX 77471

Phone: (832) 490-1600

For after-hour emergencies, please contact our dispatch team at (281) 807-9500.

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