TEXAS COMMISSION on ENVIRONMENTAL QUALITY

PROPOSED STUCTURE FOR CHAPTER 217

Subchapter A Administrative Provisions

Subchapter B Design Bases

Subchapter C Convention Collection System

PROPOSED STUCTURE FOR CHAPTER 217

Subchapter D Alternative Sewer Collection System

Subchapter E Preliminary Treatment Units

Subchapter F Activated Sludge

PROPOSED STUCTURE FOR CHAPTER 217

Subchapter G Fixed Film and Filtration

Subchapter H Natural Systems

Subchapter I On-site Treating Over 5,000 Gallons Per Day

PROPOSED STUCTURE FOR CHAPTER 217

Subchapter J Sludge

Subchapter K Disinfection

Subchapter L Safety

SUBCHAPTER AAdministrative Provisions

The proposed rule grandfathers existing facilities to the rule which was in place at the time of the facility's construction and original plans and specifications approval. This will tell the engineer and the owner of the facility what parts of a plant that will have to meet the latest design criteria during a upgrade or modification.The rule requires an operation and maintenance manual to be developed as part of the facility design. The rule provides guidance regarding which types of information should be included in the O&M manual. The existing criteria only stated O&M manual be furnished to the system owner.Clarifies TCEQ will not enforce or review for compliance with rules of other entities.

SUBCHAPTER BDesign Bases

The major change to this subchapter is to allow the design engineer to design

the plant based on the annual average flow instead of the max. monthly flow. This will allow a city to design small treatment units or to utilize existing units without need for some expansion.The draft criteria will allow a city to rerate their plant based on a lower organic loading. The criteria provides options for rerating plants based on influent organic and flow data.The draft criteria provide clearer description of the requirement for back-up power.The criteria will have a section on the reuse of effluent within the treatment process when ever possible.

SUBCHAPTER CConventional Collection Systems

SUBCHAPTER CConventional Collection Systems

Gravity PipesLift Stations and Force MainReclaimed Water and Irrigation Facilities

SUBCHAPTER D Alternative Sewer Collection Systems

Vacuum SystemPressure SewersSmall Diameter Variable Grade Sewer

SUBCHAPTER EPreliminary Treatment Units

Removes the requirement for redundant fine screens if coarse screens and a bypass are provided, unless a credit for organic reduction as a result of the fine screen is desired. The proposed criteria provides more detailed design requirements for grit removal chambers.Requires flow measurement at all facilities and provides for more detailed design requirements regarding flow measurement.

SUBCHAPTER FActivated Sludge

SUBCHAPTER FActivated Sludge

Provides design criteria for sequencing batch reactors (SBR). Provides a table to determine net solids production. Provides the equation for determination of field transfer efficiency. Draft rules state the minimum depths for diffuser submergence.Provides air flow correction factors for various diffuser submergence depths.Draft criteria changes the limitation on hopper bottom clarifiers from 25,000 gpd to 10,000 gpd or less.The draft criteria requires multiple basin and clarifiers for flows greater than 400,000 gpd.

SUBCHAPTER GFixed Film Filtration

SUBCHAPTER GFixed Film Filtration

The major change to this part of the criteria is to give credit to trickling filters for nitrification. The other changes are to provide the design engineer with better guidelines for their design of filters and fixed film reactors

SUBCHAPTER HNatural System

More flexibility in the design of wetlands systems. Updated criteria for overland flow systems. Add greater flexibility for liner installations. Criteria for evaporative pond systems.Criteria for integrated facultative lagoons.Re-instates the design criteria for Imhoff tanks.

SUBCHAPTER JSludge

SUBCHAPTER JSludge

Provides criteria for chemical pretreatment of residuals. Provides design criteria for sludge dewatering unitsRequires sludge storage for all facilities and provides design criteria for sludge storage.Provides criteria for sludge thickening technologies including: mechanical thickeners, dissolved air flotation thickeners, and centrifugal thickeners.

SUBCHAPTER KDisinfection

Requirements for disinfection, dechlorination, post aeration and sampling point locations.Providing criteria for sulfur dioxide dechlorination systems, for sodium hypochlorite and sodium bisulfite disinfection. Updates the design criteria for ultraviolet light disinfection.

SUBCHAPTER LSafety

SUBCHAPTER LSafety

Safety Audit. Job Hazard Analysis and Protective Equipment Lists