Description of WWTF No. 1 Improvements (Tin Man) Project

San Jacinto River Authority (SJRA) Woodlands Division initiated an odor control study in June 2020 to evaluate and analyze all systems and processes at Wastewater Treatment Facility No. 1 (WWTF No.1) and the collection system near the community of Lakeside Cove in The Woodlands.  The purpose of the project was to evaluate current odor control measures and technologies at the plant and collection system while also outlining potential plant and collection system modifications to improve possible odor emissions from the facility.  Results of the study were presented to The Woodlands MUDs and SJRA Board of Directors in late-2020.  The Woodlands MUDs, through the Woodlands Water Agency, approved and funded the design for the Wastewater Treatment Facility No. 1 Improvements (Tin Man) Project.

Wastewater Treatment Facility No. 1 Improvements (Tin Man) Project

Contractor:  Kimley-Horn & Associates

Village:  Grogan’s Mill

MUDs:  MUD 6

PDF Map: WWTF No. 1 Improvements

Status & Schedule

Design Time Frame:  February 2021-Winter/Spring 2022

Additional Documents:
WWTF No. 1 Improvements:  Tin-Man/Odor Control Update Presentation at the Lakeside Cove Community Meeting June 1, 2021
SDS SuperAll #38
SuperAll #38 Technical Data Sheet
Tilden Lift Station Case Study

Dates are subject to change.

Study Information for WWTF No. 1 Odor Control PER (Complete)

Contractor:  Kimley-Horn & Associates

Village:  Grogan’s Mill

MUDs:  MUD 6

PDF Map:  Map WWTF1 Odor Study

Status & Schedule

Study Time Frame:  June 2020 – October 2020

Additional Documents:
Integrated Odor Control Plan Report for Woodlands WWTF No. 1
Odor Control Plan Presentation – November 4, 2020

Dates are subject to change.

Frequently Asked Questions Regarding Odor Issue in the Vicinity of  Wastewater Treatment Facility No. 1

Built in 1975, WWTF No. 1 receives raw sewage from homes and businesses across nine Woodlands Municipal Utility Districts (MUDs):  MUD 1, MUD 6, MUD 7, MUD 36, MUD 46, MUD 47, MUD 60, MUD 67, and Metro MUD.  The average daily flow is approximately 3.5 million gallons per day.

The three WWTFs in The Woodlands are operated by the San Jacinto River Authority (SJRA) pursuant to contracts with the MUDs.  Per the contracts, the MUDs approve the budgets and capital project plans and pay for maintenance, operations, and facility expansions through the sewer rate.

WWTF No. 1, located near Sawdust Road and S. Millbend Drive, consists of mechanical and manual bar screens, a grit removal unit, four aeration basins, three secondary clarifiers, two low-head cloth media filters, and three chlorine contact basins.  The sludge handling units include aerobic digesters, a gravity thickener, and two belt filter presses.

  • Odors are normal for a plant of this type and age, but we can do something about it.
  • Considering that the plant was built in 1975 when there were no neighboring businesses or residences nearby, the plant is running as it was originally designed.
  • Operationally, the plant has consistently earned awards for Peak Performance and Wastewater Treatment Plant of the Year.
  • Over the years, as development has occurred closer and closer to the plant, odors have become more noticeable, meaning that significant upgrades will be needed to bring the plant to today’s higher standards for reduced odor.
  • These upgrades will involve both short-term and long-term fixes.

SJRA and the MUDs have taken several steps to determine sources and mitigate odor, including:

  • High pressure and vacuum cleaning of sewage lines
  • Covering grating to prevent venting from splitter boxes
  • Bypassing the plant’s grit unit
  • Inspecting manholes and repairing as needed
  • Installing inserts and solid, non-venting manhole lids
  • Expanding chemical disinfection of open roll-off containers
  • Upgrading odor control systems at the plant and installing additional units
  • Changing processes in aerated basins
  • Adjusting aeration control, monitoring, and alarming practices
  • Initiating a comprehensive odor control study in February 2020

Yes, this year SJRA and the MUDs initiated a comprehensive study to identify odor sources and recommend solutions.

  • January 2020: Texas Commission on Environmental Quality investigated reports of odor at WWTP No. 1.  No evidence of odor was found during this inspection.
  • February 2020: SJRA engaged Perkins Engineering to conduct an odor study in the neighborhood of Lakeside Cove.
  • March-April 2020: Sensors were placed throughout Lakeside Cove. Data was collected from 16 locations over four weeks.  Weekly progress and sensor locations posted to
  • May 2020: Consultant will review collected data from odor monitors and report findings in a public meeting.

Mitigation measures are being implemented right now to provide as much odor reduction as possible in the near term while permanent fixes are designed and presented to the MUDs for approval.

Results and recommendations from the Kimley-Horn and Associates odor study will be presented to the MUDs.  As the contract owner/operator, SJRA stands ready to execute any measures approved by the MUDs.

For information on Woodlands Water Agency visit their website at, call 855-426-7283, like them @WoodlandsWater and follow them on Twitter @WJPA_Water.

For additional information on the WWTF No. 1 Odor Study, call the Woodlands Division office at 281-367-9511, or contact Matt Corley at

For additional information on SJRA visit, like SJRA on Facebook @SanJacintoRiverAuthority, or follow us on Twitter @SJRA_1937, or find us on Instagram @SanJacintoRiverAuthoritySJRA.