Transcript Expanding Domestic Wastewater Reuse in Colorado

Expanding Domestic
Wastewater Reuse in
Colorado
Regulation No. 84
2004 Joint RMSAWWA/RMWEA Annual Conference
September 12-15, 2004
Wesley Carr, Environmental Protection Specialist
CDPHE/WQCD
Background

February 1998 – The Joint Reuse Committee RMSAWWA/RMWEA suggested an approach to
the Water Quality Control Commission (WQCC)
for reuse of reclaimed domestic wastewater

March 1998 – The WQCC requested a Water
Quality Forum Subcommittee be convened to
consider potential statutory changes to the Water
Quality Control Act to address use of reclaimed
domestic wastewater for landscape irrigation
Background

Fall 1999 – the Forum subcommittee
recommended the Water Quality Control Act be
amended to provide the Commission authority to
promulgate regulations for the oversight of reuse
and provide the WQCD authority to implement a
reuse program
Background

March 2000 – General Assembly adopted changes
to the Act providing the WQCC authority to
establish regulations for reuse - except for uses
related to drinking water

July 1st, 2000 – Changes effective

Reuse subcommittee concurrently developed a
control regulation modeled after the biosolids
regulation
Reclaimed Domestic Wastewater
Control Regulation No 84

WQCC adopted the
Reclaimed Domestic
Waster Control
Regulation in October
2000

Allowed for the use of
reclaimed domestic
wastewater for
landscape irrigation
Purpose

Encourage the use of reclaimed water while
protecting public health and environment

Make reuse permitting less cumbersome by
eliminating previously required discharge permits based on adequate demonstration of application at or
below agronomic rates with respect to nutrients

Notice of Authorization is the implementing platform
Reuse Program Development

After the regulation was adopted, the Reuse
Committee assisted the Division with development of
the reuse program:
- Letter of Intent forms and templates
- Notice of Authorization templates
- Committee developed public outreach pamphlets

A CWQF Workgroup consisting of the Committee, the
Division and others recently revisited the regulation
and incorporated additional uses
Landscape
Applications

Applications Permitted So far:
- Sod farms
- Schools
- Golf courses
- Ball fields
- Parks
- Medians
- Greenbelts
- Cemeteries
- Open space
- Multi-family units
- HOAs
- Business complexes
Single-Family Residential
 Single-Family
residential use is not
permitted under the
current regulation
A
CWQF workgroup
is however working on
a proposal to
incorporate this use
Development of Reuse
Water Quality Standards

Mitigate public health risk by treating water for
pathogens: viruses, bacteria & protozoan

Minimize the risk for gastrointestinal disorders
for people casually exposed to reuse water used
for surface irrigation of landscaping
Development of Reuse Water
Quality Standards

Bacteria protection is achieved through
imposing limits on E. Coli – surrogate for
bacteria pathogens

Viral & protozoan protection is achieved
through imposing limits on turbidity
Development of Reuse Water
Quality Standards

Reuse water meeting Category 2 “Unrestricted
Use” standards and used in areas with high
potential for public contact requires filtration and
turbidity limits as an additional barrier
Development of Reuse Water
Quality Standards

Reuse water meeting Category 1 “Restricted Use”
standards and used in areas having a low
potential for public contact does not require
filtration but must meet TSS limits consistent with
a well-operated secondary treatment system
Reuse Water
Quality Standards
Treatment to Category 2 “Unrestricted Use”
standards requires oxidation, filtration and
disinfection
E. Coli
126/100ml monthly geometric mean
235/100ml single sample maximum
Turbidity Not to exceed 3 NTU as a monthly
average
Not to exceed 5 NTU in more than 5%
of samples
Reuse Water
Quality Standards
Treatment to Category 1 “Restricted
Use”standards requires secondary treatment and
disinfection
E. Coli
126/100ml monthly geometric mean
235/100ml single sample maximum
TSS
30 mg/L as a daily maximum
Basis for Standards
Research
evidence shows E. Coli is the most
appropriate surrogate indicator organism for pathogens
– does not re-grow when released into the ambient
environment
Swim
beach standard for E. Coli was chosen because
criteria developed to protect swimmers will be more
protective of people casually exposed to reclaimed water
– the swim beach standard was developed based on
ingestion of 100 ml of water
Basis for Standards
Category
2 - turbidity is a relatively simple
measurement of microbial purity. Research
demonstrates an absence of virus PFUs at up to 6 NTU
when combined with disinfection. The commission
adopted a 3 NTU standard.
1 – 30 mg/l total suspended solids was
chosen because it is a standard consistent with a well
operated facility. The standard is acceptable for
application of reuse water to sites with a low-potential
for public contact.
Category
Conditions for Use Of Reuse Water
Confine
application to authorized areas:
-minimize runoff
-confine direct and windblown spray
-keep spray away from food and drinking water
Application
rates shall control ponding (surface water
and ground water protection)
Public
notification and signage shall be provided
Conditions for Use
Of Reuse Water
Pipes,
valves, outlets, controllers, tank trucks shall be
marked
Back
flow prevention devices shall be used at potable
connections
No
impoundment or irrigation within 100’ of a domestic
water supply
Workers
shall be notified of potential health hazards
Additional Conditions for Water
Meeting Category 1 Standards
Irrigate
Use
during periods when public is not present or
barriers to prevent access to the site
-barriers may not be removed until
1-hour after watering ceases
Facilities Currently Authorized
for Reuse Under Regulation 84
Facility
Capacity MGD
Anticipated MGD
City of Aurora Sand Creek Reuse
5
5
Centennial Water and Sanitation
3
1
City of Westminster
6
6
Plum Creek Wastewater Authority
3.55
1.2
City of Louisville
0.145
0.145
Upper Monument Creek
0.5
0.5
Colorado Springs - LVSWWTF
6
6
Fairways Metro District
0.107
0.103
Town of Superior
2.2
1.2
Stonegate Village Metro District
1.1
1.1
Denver Water
30
5
Broomfield Wastewater Reclamation
6
6
Parker Water and Sanitation District
3.5
1.44
67.1
34.7
Total
Recent Changes – June 30, 2004






Minor editorial changes
Reorganization of several sections
Standards categorized to help clear up
confusion unrestricted vs. restricted use
Additional uses have been incorporated
New definitions for new use clarification
New User Plan to Comply requirements to
compliment these new uses
Additional Uses Approved:


Industrial
- cooling towers
- concrete mixing and washout
- dust control
- soil compaction
- closed loop cooling systems
Commercial
- mechanized street cleaning
- zoo operations
- non-residential structure fire protection
Basis for Uses
When proper BMPs are employed for these
additional uses, the public health and
environment are protected.
Cooling Towers/
Closed Loop Cooling




No discharge – sanitary sewer
Discharge under another permit
Low potential for public contact
Water is treated higher standards
Concrete Mixing





No discharge
Cat. 1 – Mixing only
Cat. 2 – Mixing and wash down
High pH
Driver training/signage for truck supply
Dust Control/Soil Compaction



Controlled application rates
Low potential public contact
Higher potential sites require
Category 2 water and BMPs
Mechanized Street Sweepers



Controlled application rates
Low potential for public contact
No significant residue on surface
Fire Protection




Discharges exempt from NPDES
discharge permitting requirements
Fire authority approval letter
Public contact potential low –
infrequent/short duration
Fire fighter training/ additional BMPs
Zoo Operations





No discharge – sanitary sewer
No public contact with reuse water
Holding ponds/tanks lined
Category 2 water exceeds federal
water standards for zoo operation
Worker training and BMPs
Reuse Permitting - Treater

Letter of Intent








Facility information, contacts, Etc.
Information demonstrating ability to comply with reuse water
quality standards
Information on nutrient content and an agronomic analysis
Reuse system management plan – addressing public/worker
education, ability to terminate service, etc.
Evidence that reusing the water will not materially injure water
rights
A User Plan to Comply for each user
For fire protection - a letter form the FPA
Notice of Authorization – Use and Distribution
Reuse Permitting - User

User Plan to Comply – Submit to Treater




UPC Demonstrates how user will meet the conditions for
use of reuse water – templates available
Conditions outlined for ALL users
Additional conditions required based on type of use
Notice of Authorization – Use Reuse Water

Each individual user
Annual Report - Treater

Demonstration standards were met
 Information submitted to Treater by User
demonstrating the conditions of
application were met
 Evidence that the Treater conducted
inspections of users
Current CWQF Workgroup

Single-family residential reuse
 Nexus between Regulations 84, 72 and 61
 Additional uses equally/greater protective
than SF
Further Information Available @
www.cwqf.org
www.cdphe.state.co.us
www.rmwea.org
Discussion…
CONTACTS:
Wesley Carr
Reuse Management Program
WQCD-P-B2
4300 Cherry Creek Dr. South
Denver, CO 80246-1530
303-692-3613
[email protected]
John Rehring, P.E., CDM
RMSAWWA/RMWEA Joint
Reuse Committee Chair
1331 17th Street Ste. 1200
Denver, CO 80202
303-298-1311
[email protected]