Procedures to Implement the Texas Surface Water

Quality Standards

Peter SchaeferStandards Implementation

Team 512-239-4372

peter.schaefer@tceq.texas.gov

What are “Implementation Procedures (IPs)”

Procedures to Implement the Texas Surface Water Quality Standards (IPs) RG-194

A guidance document that explains how TCEQ applies the Texas Surface Water Quality Standards

IP Revision process

• Triennial review process

• 2010 IPs approved at the June 30, 2010 TCEQ Commissioner’s Agenda

• EPA approved most of the 2010 IPs on July 12, 2013

• Next water quality standards revision: 2017

• Next IPs revision also targeting 2017

Unresolved EPA Objections to 2010 IPs:

• Dechlorination • Variances

• Whole Effluent

Toxicity

Focus of 2017 IP Revisions• Updates to dechlorination requirements for

minor municipal discharges• Variances• Reasonable Potential for WET Testing• Temperature • Ambient WQ data updates• Industrial cooling water impoundments

definitions• Updates to endangered species• 316(b) rule implementation• Updates to MALs• Correcting errors/ommissions in current IPs

Dechlorination

IPs propose dechlorinationrequirements for renewing,

new, and expanding domestic discharges with design flows between 0.5 and 1.0 MGD

Variances

IPs address site specific standards and variances.

EPA objection -specific date for compliance with final effluent

limits

Biomonitoring Review

• Focused on “WET”-Whole Effluent Toxicity

• Exposure of invertebrate and vertebrate species to predict impacts to aquatic life (lethal and sublethal)

• Uses the most recent 5 years of testing, determines reasonable potential

• Formulates language, and “Toxicity limits”

EPA Objection to 2010 IPs

•EPA wants Reasonable Potential determination process for WET limits within IPs

•Ongoing discussions with EPA to come to agreement

Toxicity Reduction Evaluations

• TREs are now voluntary. Although no longer

• mandatory, they are strongly encouraged.

• A successful TRE is dependent upon a defining

• reasonable potential to assure that sublethal toxicity is

• persistent and significant.

Temperature

• Temperature screening stakeholder group started in August 2014

• TCEQ is taking initial comments and working on detailed procedures for inclusion in the IPs

• Draft procedures to be presented to stakeholders in summer 2016

Temperature RP analysis

• Heat balance equation

• Numerical model calculations (ex. Cormix)

• Highly site-specific technical analysis

Ambient Water Quality Data

• Routine water quality data is analyzed to derive segment-specific values

• TSS, pH, hardness, TDS, chloride, sulfate

316(b)-Intake Structures

• EPA’s final rule for existing facilities became effective October 14, 2014

• TCEQ working with EPA and permittees on application/information requirements and implementation issues

• Court challenges still pending

Endangered Species

•New listings

•De-listings

MAL’s

Changes to Minimum Analytical Levels (MALs) -

now in effect

Nutrients 2010 IPs

• Streams and Rivers- narrative

• Lakes – numeric and narrativelocal effects in reservoirsmain body

• Bays and Estuaries

Nutrient Screening

• Phytoplankton in open water

• Attached algae; floating algae

• Rooted vegetation

• Aesthetic effects on recreation

• Water supplies: THM, taste & odor

• Aquatic-life: fisheries ↑↓ habitat ↑↓

• DO at night↓ diversity↓

IPs – Nutrient Narrative Criteria

30 TAC Chapter 307.4(e):

“Nutrients … shall not cause excessive growth of aquatic vegetation which impair an

existing, attainable, or designated use.”

Nutrients – Typical TP Limits

Permitted Flow (MGD) TP Limit (mg/L)

< 0.5 1.0

0.5 – 3.0 1.0 – 0.5

> 3.0 0.5

Site specific- 0.15 mg/L TP limits

Nutrients – Nitrogen Limitations

• TN limitations to prevent potential impact to sea grass communities.

• Consideration of site specific conditions influencing dispersion and discharge volume in relation to the proximity of sea grasses to outfall.

• In the absence of numeric criteria, nitrogen limit recommendations are based on Best Professional Judgment (BPJ) and available site specific data.

Reservoir Criteria• Criteria were

proposed for 75 reservoirs

• EPA approved about half of the criteria proposed

• How does that affect me??

pH Screening Procedures

• Screening procedure established with EPA concurrence for certain direct discharges to classified segments

• pH Sceening conducted: • for major municipal

facilities (≥1 MGD flow)

• for industrial discharges

IP Revisions• Update Segment ambient WQ

data

• Temperature – cooling water

• WET -RP analysis

• Decholorination

• pH Objections

• Variances

• Endangered species

• MALs

• 316(b) rule implementation

• General updates

Any

Questions

???