Title: Expanding Domestic Wastewater Reuse in Colorado Regulation No. 84
1Expanding Domestic Wastewater Reuse in
ColoradoRegulation No. 84
- 2004 Joint RMSAWWA/RMWEA Annual Conference
- September 12-15, 2004
- Wesley Carr, Environmental Protection Specialist
- CDPHE/WQCD
2Background
- 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
3Background
- 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
4Background
- 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
5Reclaimed 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
6Purpose
- 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
7Reuse 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
8 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
9 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
10Development 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
11Development 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
12Development 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
13Development 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
14Reuse 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
15Reuse Water Quality Standards
- Treatment to Category 1 Restricted
Usestandards 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
16Basis 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
17Basis 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. - Category 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.
18Conditions 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
19Conditions 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
20Additional Conditions for Water Meeting Category
1 Standards
- Irrigate during periods when public is not
present or - Use barriers to prevent access to the site
- -barriers may not be removed until
- 1-hour after watering ceases
21Facilities 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
Total 67.1 34.7
22Recent 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
23Additional 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
-
24Basis for Uses
- When proper BMPs are employed for these
additional uses, the public health and
environment are protected.
25Cooling Towers/ Closed Loop Cooling
- No discharge sanitary sewer
- Discharge under another permit
- Low potential for public contact
- Water is treated higher standards
26Concrete Mixing
- No discharge
- Cat. 1 Mixing only
- Cat. 2 Mixing and wash down
- High pH
- Driver training/signage for truck supply
27Dust Control/Soil Compaction
- Controlled application rates
- Low potential public contact
- Higher potential sites require Category 2 water
and BMPs
28Mechanized Street Sweepers
- Controlled application rates
- Low potential for public contact
- No significant residue on surface
29Fire Protection
- Discharges exempt from NPDES discharge permitting
requirements - Fire authority approval letter
- Public contact potential low infrequent/short
duration - Fire fighter training/ additional BMPs
30Zoo 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
31Reuse 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
32Reuse 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
33Annual 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
34Current CWQF Workgroup
- Single-family residential reuse
- Nexus between Regulations 84, 72 and 61
- Additional uses equally/greater protective than
SF - Further Information Available _at_
- www.cwqf.org
- www.cdphe.state.co.us
- www.rmwea.org
35Discussion
CONTACTS
Wesley Carr Reuse Management Program WQCD-P-B2 430
0 Cherry Creek Dr. South Denver, CO
80246-1530 303-692-3613 wes.carr_at_state.co.us
John Rehring, P.E., CDM RMSAWWA/RMWEA Joint Reuse
Committee Chair 1331 17th Street Ste.
1200 Denver, CO 80202 303-298-1311 rehringjp_at_cdm.c
om