Expanding Domestic Wastewater Reuse in Colorado Regulation No. 84

1. Expanding Domestic Wastewater Reuse in ColoradoRegulation No. 84 2004 Joint RMSAWWA/RMWEA Annual Conference September 12-15, 2004 Wesley Carr, Environmental Protection Specialist CDPHE/WQCD

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

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

10. 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

11. 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

12. 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

13. 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

14. Reuse Water Quality Standards Treatment to Category 2 “Unrestricted Use” standards requires oxidation, filtration and disinfection E. Coli126/100ml 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

15. 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

16. 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

17. 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. • 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.

18. 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

19. 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

20. Additional 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

21. Facilities Currently Authorized for Reuse Under Regulation 84

22. 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

23. 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

24. Basis for Uses When proper BMPs are employed for these additional uses, the public health and environment are protected.

25. Cooling Towers/ Closed Loop Cooling • No discharge – sanitary sewer • Discharge under another permit • Low potential for public contact • Water is treated higher standards

26. Concrete Mixing • No discharge • Cat. 1 – Mixing only • Cat. 2 – Mixing and wash down • High pH • Driver training/signage for truck supply

27. Dust Control/Soil Compaction • Controlled application rates • Low potential public contact • Higher potential sites require Category 2 water and BMPs

28. Mechanized Street Sweepers • Controlled application rates • Low potential for public contact • No significant residue on surface

29. 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

30. 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

31. 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

32. 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

33. 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

34. 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

35. Discussion… CONTACTS: Wesley Carr Reuse Management Program WQCD-P-B2 4300 Cherry Creek Dr. South Denver, CO 80246-1530 303-692-3613 wes.carr@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@cdm.com