2015-11-02 Committee on the Environment Minutes
MINUTES
CITY COUNCIL COMMITTEE ON THE ENVIRONMENT
November 2, 2015
After determining that a quorum of the Committee on the Environment of the Denton City
Council was present, the Committee on the Environment thereafter convened into an Open
Meeting on Monday, November 2, 2015 at 1:36 p.m. in the City Council Work Session Room
215 E. McKinney, Denton, Texas.
Present: Council Member Dalton Gregory, Council Member Joey Hawkins and Council
Member Keely Briggs
Also Present: Howard Martin, ACM; Kenneth Banks, Environmental Services and Sustainable
Director; Katherine Barnett, Sustainability and Special Projects Adm; Deborah
Viera, Environmental Compliance Coordinator; Matthew Hendrix, Storm Water
Specialist; Kathy Jack, Conservation Program Coordinator; Kim Mankin,
Administrative Supervisor and Annie Bunger, Administrative Assistant III
1. REGULAR MEETING:
A. COE15-012
Consider approval of the Committee on the Environment meeting minutes of October 5, 2015.
Approved as circulated
B. COE15-011
Receive a report from Dr. Fouad Jaber, Texas A&M Agrilife Extension, and hold a discussion
regarding the use of porous concrete and related materials in development and construction.
Dr. Jaber talked about why we need to treat stormwater. There was information on the local
hydrologic cycle. Naturally very little of rainwater ends up in a river. When it does it is very
clean as it runs through sand and captures the pollutants. When we urbanize we move trees and
actually convert the land to impervious, what is not impervious we add grass and grade it in a
straight fashion where it runs toward the street. As a result you have larger amount of water
faster flow and add pollutants. Jaber then showed a graph of an area pre-development and post
development. There was some discussion how a 100 year storm is calculated which for this area
is nine and a half inches in a 24 hour period.
Jaber talked about the prevention of stormwater pollution including better management, reducing
stormwater volume and reducing contaminant content. All rivers and lakes need protection
including the coastlines, riparian zones and pathways to the water body.
Low impact development was introduced with examples of rain garden bio-retention areas,
porous pavements, green roofs and rainwater harvesting.
Types of permeable pavement includes; paver blocks, porous asphalt, porous concrete, turf paver
and expanded shale mix.
Minutes of Committee on the Environment Meeting
November 2, 2015
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Gregory asked about freezing weather and permeable pavement, would there be pot holes
like with traditional pavement. Jabar answered no, they are commonly used in New York and
other areas with freezing temperatures. When you get rain that sits on non-porous materials it
ices. With the porous materials it flows out. Jabar has this material in his parking lot in Dallas,
this Committee can go and look if they would like. The material has been there for two years
and have no signs of cracks or other problems.
Gregory asked what is more cost effective, porous asphalt or porous concrete. Jabar
answered asphalt is cheaper but has its own set of issues. Average concrete is $6 per square foot.
Porous asphalt $8-$9 per square foot, porous concrete $10-$12 per square foot, paver blocks are
more expensive probably $16 per square foot. There are other items such as piping that would
also figure into the costs.
Gregory then asked the cost comparison for turf paver and expanded shale mix. Jabar
answered the both cost in the range of $5 per square foot. Remember they are limited in use.
Hawkins asked if the current code or ordinances allow for if a developer uses porous
materials. Banks answered Denton has a maximum parking standard where most cities have a
minimum parking standard. If you exceed the maximum allowed amount of parking spaces for
the type of use the code requires you to use permeable surfaces in that exceedance.
Jabar asked if there is a drainage requirement. Banks answered there is, the drainage
requirement is sized to the impermeable surfaces and the permeable surfaces are not going to add
an addition to that drainage requirement. This addresses the stormwater quality and quantity.
Gregory added at least part of the parking lot on Exposition that will be re-build could be
convertible from parking to green space. Another portion of the parking lot could be
porous surface so we would have experience with it. Gregory then asked if there are any in
the City. Banks answered Fire Station 7, Hunter added the new Wastewater Treatment
Administration building has impervious pavement.
Jabar showed pictures of typical applications. Paver material is not recommended for heavily
traveled streets, but works well on lightly used slower streets or alleyways.
A permeable pavement experiment was conducted on a parking lot in Dallas comparing five
types of pavement. There were 25 experimental stalls among 52 total functional stalls. There
was a perforated underdrain piping system with a total thickness of 16 inches. This was
hydrologically separated with concrete curbs. The analysis was shown on a bar graph. Volume
reduction rates were as follows: PICP, 71 percent; pervious concrete, 74 percent; grass pavers,
78 percent; and gravel pavers, 93 percent.
Results for the experiment concluded the percent contribution other than TSS appeared high
because of the minute amounts found in the control runoff. Nitrate and orthophosphate
concentrations were still low in general from all treatments. Permeable pavement is constructed
to collect runoff from paved areas with a minimum amount of soluble chemicals in the water and
TSS is the major target pollutant.
Minutes of Committee on the Environment Meeting
November 2, 2015
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Briggs stated that in preparation for the 100 year flood the City has taken natural creek
beds and busted them up and filled them with 50 feet of concrete, is this type of concrete
better for that application. Jabar asked if the channels are being lined. Staff agreed. Jabar
said he is a natural stream restoration specialist. Pervious channel is an eco-system that needs
the soil. There is a cross section design of the system that needs to be looked at. Systems can be
put in the watershed everywhere and guarantee that less water will end up in the channel and
there would be no need for channelization. There are budget issues with different systems.
Banks added that some of the approaches that were talked about today would prevent excessive
flows for the future and as new development happens. Jabar agreed and added that if someone
donated $2 million to restore a stream, if you are going to urbanize the watershed more all the
money would be wasted because the flow would increase. In order to prevent and protect the
investment in the streams low impact development is necessary.
Gregory asked as we are performing the street rebuilding projects of using more pervious
asphalt would it slow down the storm drains. Banks answered one of the key issues would be
the extra flow that is generated from all the new development that is coming into the city. The
new subdivision is going to be comprised of streets but would have additional sources of
imperviousness or conveyance of water. There are homes and sloped yards all designed to move
water off of the site. These types of methods that deal with one component of low impact
development but actually putting in other types of stormwater management is a broader context.
That can be dealt with traditional methods like detention facilities but can also we dealt with
much more distributed methods like at Rayzor Ranch.
Briggs stated she was referring to the concrete channel that was constructed a couple of
weeks ago and asked if there are plans to do more channels the same way. Martin answered
it depends on which channel that is being talked about. Briggs stated there are a lot. Martin
stated those that were never designed to carry the 100 year flood will technically have to be
enlarged. When you get to the undeveloped component of the City those have not been
concreted they are natural. The example is the area that goes by Woodrow by the old animal
shelter which is all natural, that will not be concreted. The areas in town that are developed and
being developed currently will more than likely receive come kind of rebuild that would include
concrete channel lines.
Gregory suggested asking for an item regarding the channels.
Martin added what we are talking about here are more applicable to the upper parts of the
watershed and new development versus those that are already developed with an undersized
drainage channel existing.
Gregory asked if there are any funds available from TCEQ or other organizations that
would want to promote more use of this type of paving.
Jabar stated that every year the TCEQ has 319 funds available for Cities and other entities to
actually install best management practices that reduce non-point source pollution. There is no
better example for a City than low impact development.
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November 2, 2015
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Gregory asked if we apply for those. Banks answered yes, we have received $1.3 million since
the 2005 Management Practices that have been installed.
Gregory added that this was very informative.
C. COE-15-013
Receive a report and hold a discussion regarding the new Municipals Stormwater Permit for the
City of Denton.
David Hunter gave this presentation. The Watershed Protection Divisions main goal currently is
the Phase II MS4 Stormwater Permit and be compliant with the Clean Water Act.
The origins of the watershed protection program go back many years to the pretreatment
understanding of handling waste, load and inspections.
Storm-Water Phase II permitting went online in 2003 for cities under 100,000.
their permitting process until 2007. This includes the Clean Water Act and the Safety Water
Drinking Act.
Our water goes down to Lake Lewisville which is one of our drinking water supplies.
Contaminants are easier and cheaper to control in the watershed (pollution prevention) than to
remove once in the reservoir, via Water Treatment Plant.
Timeline of the Texas Stormwater Permitting:
2003 Construction Permit (2003-2008)
2006 Industrial Permit (MSGP) (2006-2011
2007 Phase II MS4 Permit (2007-2012)
2011 Industrial Permit Reissued
2013 Construction Permit Reissued
2013 Phase II Stormwater Permit Reissued
MS4 Definition: A conveyance or system of conveyances owned by the U.S., a state, city,
county, town, or other public entity that discharges to waters of the U.S. and is designed / used to
collect or convey storm water. The systems is not a combined sewer.
Gregory asked as the City gets larger will there be more of a requirement for more
mitigation activities of the stormwater before it gets into the lake. Hunter agreed and added
with the new permit the City is called a large or category 4 phase II. The City is the largest of
the phase II and has more requirements to mitigate any pollution.
Hunter stated that under the law the City regulated what is called the urbanized area of Denton.
Banks added that both universities are required to have their own MS4 permit. It is like having
two cities within a City.
Requirements of the stormwater permit include:
Develop and Implement Comprehensive Storm Water Management Program (SWMP):
Minutes of Committee on the Environment Meeting
November 2, 2015
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Reduce Pollution in Storm Water to the Maximum Extent Practicable (MEP) federal standard
Protect Water Quality
Meet Water Quality Requirements of Clean Water Act and Texas Water Code
Required inside of UA only
Include Six Minimum Control Measures (MCMs):
Programs and Controls
Best Management Practices (BMPs)
Compliance under the new permit has Denton as a Large Phase II MS4
The six minimum measures include:
Public Education, Outreach, and Public Involvement
Illicit Discharge Investigation and Elimination
Construction Regulation
Post Construction
Municipal Good Housekeeping and Pollution Prevention
Industrial Sources
Public Education outreach and involvement:
All permittees shall develop, implement, and maintain comprehensive stormwater education and
outreach program to educate public employees, businesses, and the general public of hazards
associated with the illegal discharges and improper disposal of waste and about the impact that
stormwater discharges can have on local waterways, as well as the steps that the public can take
to reduce pollutants in stormwater. Examples include: Stream Clean, Great American Clean Up
Jazz Fest, Redbud Days, Website and Facebook, Survey Research, Brochures, Reverse Litter and
DTV.
Gregory stated we could have a Committee on the Environment meeting at the Wastewater
Treatment Plant.
Illicit Discharge Detection and Elimination (IDDE)
All permittees shall develop, implement and enforce a program to detect, investigate, and
eliminate illicit discharges into the small MS4. The program must include a plan to detect and
address non-stormwater discharges, including illegal dumping to the MS4 system. The
stormwater map is online.
New requirements include:
Dry Weather Screening
Source Investigation
Identification of Priority Areas
Field Screening
Field Observation
Construction site stormwater runoff control.
All permittees shall develop, implement and enforce a program requiring operators of small and
large construction activities, as defined in Part I of this general permit, to select, install,
implement, and maintain stormwater control measures that prevent illicit discharges to the MEP.
The program must include the development and implementation of an ordinance or other
Minutes of Committee on the Environment Meeting
November 2, 2015
Page 6 of 8
regulatory mechanism, as well as sanctions to ensure compliance to the extent allowable under
state, federal, and local law, to require erosion and sediment control.
Stormwater compliance map was reviewed.
Post-Construction Stormwater Management in New Development and Redevelopment.
All permittees shall develop, implement and enforce a program, to the extent allowable under
state, federal, and local law, to control stormwater discharges from new development and
redeveloped sites that discharge into the small MS4 that disturb one acre or more, including
projects that disturb less than one acre that are part of a larger common plan of development or
sale. The program must be established for private and public development sites. The program
may utilize an offsite mitigation and payment in lieu of components to address this requirement.
As with changes the sites will be required to be inspected.
Hunter then talked about pollution prevention and good housekeeping for municipals operations.
Examples include street sweeping, home chemical collection center, and dyno dirt. Those are
things that are sustainable that keep the pollutants off of the streets.
New requirements for stormwater compliance include:
Operation and Maintenance and Materials Management Programs
Training and education
Inventory of Sites
Assessment of Operations
Regular Inspection of Sites
Storm Sewer System Operation and Maintenance and Cleaning
Sweeping Waste Management Program
List of Problems areas
Facility Assessment and Prioritization
The monitoring program was then talked about.
The City has 88 sites in and around the City.
Continuous Monitoring at ends of Watershed and in Lake Lewisville
Permanent Monitoring Sites
Volunteer Monitoring
Water Quality
Benthic Monitoring
Rainfall Monitoring Sites
Zebra Mussels Monitoring in Lake Lewisville
A map of the sites were shown as well as instrument information.
The use of the data that is collected can show water quality trend analysis, regulatory compliance
and the use with GIS to characterize watersheds and find hot spots.
Maps with areas of elevated Diazinon concentrations from March 2001 and April 2001 were
shown. This pr-
product concentration at the Wastewater Treatment plant.
Minutes of Committee on the Environment Meeting
November 2, 2015
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Briggs asked if the EPA had not banned this product, what as a City could we do in a
situation like this. Hunter answered that since the stormwater is a separate system a lot of our
focus went to closing up cracks in the sanitary sewer system where that stormwater was leaking
in. The other part had to do with public education and outreach,
Hunter added that the question was asked if there was money received in a 319 grant. The
money has been received and a portion used on the Hickory Creek Water Protection Plan which
essentially tries to handle some of the water quality impacts from post construction. It also
looked at places like Cole Ranch and how to address water quality with a large development a
master plan community.
Hunter gave examples of where our current water quality Best Management Practices are
located: Dog Park at Lake Forrest, Fire Station 7, Airport, Cross Timbers Park, and South Lakes
Park.
many up-front expenditures paid for
by grants. Partnership with Universities and other entities provides experience, expertise and
additional resources. Bottom line is more extensive program at less cost, greater opportunities
for outreach, education and public participation.
Across the City the Stormwater Permit is not just Watershed Protection other entities include:
Wastewater
Water
Solid Waste
Parks and Recreation
Library
Streets and Drainage
Planning and Building Inspection
Gas Well Regulations
Police and Fire
Community Improvement Services
Transportation
Current Staff includes:
1 Manager (Also over Industrial Pretreatment Division)
1 Watershed Coordinator
1 Environmental Compliance Coordinator
1 Stormwater Specialist
1 Stormwater Inspector
3 Interns
Regional Projects/Partnerships:
NCTCOG - Stormwater Group and Public Works Group
National Weather Service
Reverse Litter
Evapotranspiration Network
Minutes of Committee on the Environment Meeting
November 2, 2015
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Local Stakeholders Residents and Businesses
Additional MS4s - UNT/TWU/Denton County and Other neighboring Cities
With the new stormwater permit:
Denton being classified as a Large Phase II MS4 - More regulatory requirements, tracking and
inspections.
Good News! Because of the approach we took 14+ years ago we are really in compliance with
most aspect of the new permit.
Other City Departments are doing a lot that counts for our regulatory compliance.
The Stormwater Management Plan is located on:
www.DentonWatersheds.com
D. COE15-014
ACM Update:
1. Matrix.
CONCLUDING ITEMS
A. Under Section 551.042 of the Texas Open Meetings Act, respond to inquiries from the
Committee on the Environment or the public with specific factual information or recitation of
policy, or accept a proposal to place the matter on the agenda for an upcoming meeting AND
Under Section 551.0415 of the Texas Open Meetings Act, provide reports about items of
community interest regarding which no action will be taken, to include: expressions of thanks,
congratulations, or condolence; information regarding holiday schedules; an honorary or salutary
recognition of a public official, public employee, or other citizen; a reminder about an upcoming
event organized or sponsored by the governing body; information regarding a social, ceremonial,
or community event organized or sponsored by an entity other than the governing body that was
attended or is scheduled to be attended by a member of the governing body or an official or
employee of the municipality; or an announcement involving an imminent threat to the public
health and safety of people in the municipality that has arisen after the posting of the agenda.
Gregory - Sustainability Plan Workshop December or January
Briggs - Green Sense Program to extend to Commercial
Briggs - Increase funds for Green Sense Program
Briggs - Report on Methane Emissions and air pollution
Briggs - Strategy that the City has for purchasing a tree stand
The meeting was adjourned by consensus at 3:37 p.m.