Municipal Stormwater Program Middle Rio Grande Watershed

New Mexico

Bill Honker, Water Division US EPA Region 6

Presentation Outline

Brief background on stormwater law and rules History of municipal stormwater permitting in NM Development of Middle Rio Grande areawide

stormwater approach and permit Innovative approaches in the areawide permit Status of implementation

Regulatory Background

1987 – Congress added section 402(p) to CWA establishing the NPDES Stormwater Program

1990 – Phase I regulations for large and medium

Municipal Separate Storm Sewer Systems (MS4s) 1999 – Phase II regulations for small MS4s 2003 –Census 2000 defined urbanized areas subject to

small MS4s permit requirements

Albuquerque Urbanized Area (UA) MS4 Permitting History

Phase I – Individual permit for large MS4s: - 1st permit issued Dec. 2003 and reissued Jan 2012 - Permittees: Albuquerque, AMAFCA, NMDOT, UNM

Phase II –State wide general permit for small MS4s - Permit issued June 2007, expired June 2012 - Required NOIs and SWMP submittals by municipalities - Reissuance proposed for small MS4s outside MRG area

MRG Urbanized Area MS4 permit – Combined Phase I (large MS4s) and Phase II (small MS4s) into

one General Permit for the Albuquerque UA

Middle Rio Grande Basin Albuquerque Urbanized Area

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Regulated Entities - MRG MS4 Permit

Albuquerque Rio Rancho Bernalillo County Sandoval County UNM AMAFCA SSCAFCA Flood Control

Authority ESCAFCA NMDOT District III

Town of Bernalillo Los Ranchos de Albuquerque Village of Corrales Pueblo of Sandia Pueblo of Isleta Pueblo of Santa Ana State Fairgrounds/EXPO NM Sandia National Labs/USDOE Kirtland AFB

MRG MS4 Permit Development Ten meetings, hearings, and workshops held with

stakeholders over 4-year period Stakeholders included permittees, local officials, home

builders and developers

Coordinated closely with NM Office of State Engineer to ensure consistency with State water law

Coordinated closely with NMED throughout process Integrated with Urban Waters Federal Partnership effort

in the MRG area

MRG MS4 Permit (NMR04A000)

Issued in December 22, 2014 and modified on April 9, 2015 and February 10, 2016 to remove schedule conflicts and to allow more time to review and approve Notice of Intents (NOIs) and Monitoring Plans

Sixteen NOIs approved Addresses water quality impairments

DO, Bacteria, PCBs, temperature, nutrients

Incorporate TMDLs for E. coli. Addresses endangered species and habitat concerns Rio Grande silvery minnow

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MRG MS4 Permit (NMR04A000) The post construction standard in the permit is an important

element to protect water quality and endangered species (similar requirement was part of 2012 Phase I MS4 permit for the area).

- Watershed modeling was carried out to show that the 90th

percentile storm event is a reasonable approximation of natural hydrology for the Middle Rio Grande watershed.

- The permit requires regulated entities to develop

approaches to mimic predevelopment runoff hydrology, but only up to the 90th percentile storm for new development and 80th percentile storm for redevelopment.

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MRG MS4 Permit (NMR04A000) Addressed Water Rights issues with the Office of the State

Engineer - The permit specifically cites the New Mexico Water Law - Flexibilities are included for alternative ways to comply to avoid

conflicts with New Mexico Water Law

Accommodates and encourages cooperative programs among permittees

- Could reduce compliance costs - NOT mandatory - NOT all or nothing, can be just particular program elements

(e.g., monitoring, education, etc.)

Flexibility to choose or adapt GI/LID approaches suitable for arid and semi-arid areas

Adapting Innovative Stormwater Management Techniques in Arid/semi-arid

Climates GI/LD in New Mexico may not be “green” at all

Technology Transfer GI Demonstration Project

City of Albuquerque Native Plantings Photo courtesy of the City of Albuquerque

Photo courtesy of the Sites Southwest Photo courtesy of City of Albuquerque

and Watershed Management Group

Cost can be reduced by reusing materials

Albuquerque Open Space Visitor Center High Desert Community

Green Infrastructure Can Save Money

Retaining stormwater with green infrastructure practices can reduce or eliminate the need for other water infrastructure that is currently required (e.g., pipes, detention ponds)

Minimizing impervious surfaces and preserving existing green space reduce construction costs and decrease the total amount of stormwater discharges

Photo courtesy of the City of Albuquerque

Examples of Local Resources for Arid GI/LID NM Office of State Engineer Guide to Rainwater Harvesting

http://www.ose.state.nm.us/WUC/wuc_rainwater.php

Bernalillo and Southern Sandoval Counties publication on arid GI/LID projects in area as of 2015 http://www.aridlid.org/wp-content/uploads/2014/10/ARIDi-LIDpackage-2015-small.pdf

Resources on Green infrastructure and Low Impact

Development in Arid Environments (site administered by Ciudad Soil and Water Conservation District): http://www.aridlid.org/lid-learning-resources/

Sampling storm water in arid/semi-arid climates

Photos courtesy of City of Albuquerque and TeTratech

The typical storm event is high intensity and short duration, making it challenging to obtain the needed samples.

The usage of automated sampling on ephemeral, natural channels is also logistically challenging.

- The flow path of the runoff varies along the floor of the channel. - Placement of automated sampling equipment within this type of environment is extremely challenging and can lead to loss of equipment due to the variations in flow paths.

Challenges

Twelve entities are participating in the program.

Assess the effect of storm water discharges on the Middle Rio Grande.

Two initial sampling locations (North and South in the watershed) to capture all inputs to the river within the Urbanized Area.

At minimum four grab samples spaced at a minimum interval of 15 minutes each will be collected during storm events.

Qualifying storm event is defined as a 0.25-inch or greater storm anywhere in the watershed that creates a discharge to the Rio Grande.

Cooperative Wet Weather Monitoring Program

Photo curtesy of MS4s participating in the cooperative wet weather monitoring program

Modification of Monitoring Plan from External Information In response of new information of potential source of contaminants discharging to the river, the Sampling Cooperative Program may add additional monitoring locations immediately downstream of the discharge point to the river. A hydrograph timing model for rain events in the

watershed will be used to identify which sub-watersheds discharged water to the Rio Grande during the rain event.

The monitoring results can trigger a pollutant-specific response plan.

Cooperative Wet Weather Monitoring

Continue providing technical assistance on permit implementation, including implementation of the post-construction standard GI/ practices flow paths.

Encourage cooperative programs between multiple MS4 as a way to enable cost savings and better coordinated programs across jurisdictions.

Evaluate the program and adjust over time Document program implementation – Annual Report

Next Steps

EPA:

Permittees: