Title
Annual Update on the Wastewater System
Body
Overview
The DPU wastewater operations comprises two different divisions of operations:
1) Wastewater collections (WWC [GWS])
2) Wastewater treatment & reclamation (WWT)
The GWS-WWC crew allocates two to four crew members to perform scheduled O&M work, such as mainline flushing and lift station maintenance. The GWS/WP electricians (2) also perform support work on the lift stations, as they require considerable electrical work. There are twenty-six lift stations in the WWC system with varying electrical service sizes, depending on the power of the pumps. There are currently three 480V lift stations, and twenty-two 240V or 277V lift stations.
The GWS crew operates various equipment to maintain the WWC system:
• Inspection tools - SL-RAT sonic wave detector and in-pipe video cameras for both mainline & service line applications
• Flushing tools - vactor trucks/equipment, flushing trailer equipment, “easement machine” flushing equipment for very tight access areas
• Root cutters (mainline and service)
A new chemical treatment method has been researched and instituted on the wastewater collections system. Problem areas prone to grease and septic grit deposits, as well as all of the lift stations (some require frequent treatment) are being treated with chemical agents designed to break down problematic components in wastewater that can cause catastrophic deposits (clogs). For more information on the chemical solvent treatment, see: https://www.marc1.com/marc-76-x-treme-sewer-solvent.html.
The WWT operations division oversees the operation and maintenance of the two treatment plants in Los Alamos County - LA WWTP and the new WR WRRF. The LA WWTP processes (treats) approximately 0.8 M gallons per day and produces approximately 300 lbs. of solids per day, while the WR WRRF processes approximately 0.3 M gallons per day and produces approximately 150 lbs. of solids per day.
The two plants use somewhat different treatment methods: The LA WWTP is an activated sludge/aeration basin system, while the new WR WRRF utilizes an innovative space-saving oxidation ditch technology. The NPDES discharge permits differ between the two plants due to their relative ages. The new NPDES for White Rock is more stringent than that for the LA plant. Both plants run optimally well and can easily meet the permit discharge requirements.
Both plants produce class-1A effluent, which is the best quality treatment possible. The WWT division also processes all solids in an in-house EPA-permitted compost facility that produces a high-quality, beneficial compost for domestic and industrial re-use.
WWC & WWT Accomplishments
• Enhanced public awareness campaigns for both the wastewater collections, and the treatment of the County’s wastewater. This program is vital to educate customers on their responsibilities, and what the costs and efforts are for the County to manage the systems.
• Completion of WR WRRF - incrementally put into service on 5/14/2024; fully functional by fall/winter 2024/25. Filtration and solids handling were finished by the late summer 2024
• Completion of LA WWTP filtration system - tremendously improved the total suspended solids parameters in the treated effluent.
• Working through, and learning the new treatment process at the WR WRRF.
• Researched and developed a process for repairing and upgrading old, worn MCC buckets for the motor starters at the LA WWTP.
• Assessed problems with heat-related shutdowns on the aeration blowers.
• Meeting with HVAC vendors/installers to assess the feasibility of converting the aeration blower building to heat pump cooling, and reconfiguring the air flow - assessing how to coordinate this project with in-house project management for cost savings.
• Replaced/rebuilt some of the MCC buckets at the LA WWTP due to some motor start failures.
• Continued to meet and exceed the NPDES permit parameters at the WR WRRF, and with the new filtration equipment at the LA WWTP, those parameters are now exceeding the permit requirements.
• WWT apprenticeship program has successfully trained all staff members to achieve Operator Certifications through the NMED Utility Operator Certification Program, with one staff member achieving a Level-III certification, which promoted him to a Senior Operator. Other staff members have achieved Levels II.
• County job descriptions for the DPU WWT staff needed revisions to reflect the requirements for Apprentice, Operator, and Senior Operator level positions to match the NMED State UOCP requirements.
• GWS WWC crews were able to replace two sections of exposed (aerial) pipe that were failing and leaking. The jobs were difficult and required many crew members working around the clock to get accomplished.
• Integrated 23 lift station SCADA remote sensing systems for automated sensing and call-out alerts. This has resulted in several important improvements such as catching failures before they occur.
• Completed the full rehabilitation and upgrades to El Gancho and Paseo Penasco lift stations. Began the projects for the North Road and Los Arboles lift stations.
• Main Line Flushing: 101,500 feet.
• Upgraded the server at the LA WWTP for integrating the new controls system and serving as a backup to the WR WRRF. This is a major improvement beyond the old control system that had become quite out of date at the LA WWTP.
• All GWS staff are fully trained on all WWC equipment and response procedures.
• Cross training for all WWT operators in laboratory and reporting procedures.
WWC & WWT Challenges
• Extreme use of the vactor trucks - DPU has two vactor truck units, both of which are very heavily used. Under these extreme operating conditions, one or both is commonly out of commission, negatively affecting workflow on several processes.
• Staff resources - the system’s large amount of older vitrified clay pipes puts a premium crew maintenance. The work is slow, time-consuming, and tedious, requiring a lot of hands to haul hoses and equipment into very tight and difficult-to-reach locations.
• The system takes a lot of time to maintain, and is very hard on equipment.
• Aging infrastructure - clay pipes that allow root intrusion and are prone to cracks and breaks with shifting soils.
• Problematic infrastructure - older, non-standard installations in backyards, etc. Some lines are located under homes’ foundations and are very difficult to maintain frequently.
• Flushable wipes and debris (ex. mop heads, clothing, cotton towels and rags); proliferation of these materials causing clogs and backups.
• Lift Station maintenance now requires chemical treatment for grease breakdown.
• New, more frequent (and expensive) testing requirements at the LA WWTP due to periodic influent volumes that exceed 1M gallons/day.
• Treatment plant equipment and facility upkeep - a never-ending job.
• New technology and changes in operating procedures.
• Training
• Safety
Strategic Planning
• Continue to invest in workforce - WWC-GWS and WWT staff.
• Engaged and well-trained workforce is critical to the WWC-GWS and WWT divisions.
• Develop & update workflow SOPs to continually have focused benchmarks, such as reducing overflows, backups, lift station failures, and customer crisis calls.
• Crosstrain staff on all workflows.
• WW Collections is very equipment intensive - ensure equipment is well-maintained and rotated/replaced before critical failures occur.
• DPU continues to address the vactor maintenance issues with LAC-Fleet because it is critical for situational response. They have improved with response time, but having critical parts on-hand continues to be an issue.
• Lift stations need constant attention. Continue to refine maintenance SOPs to catch critical problems before they occur, i.e. pump motor & electrical testing, panel component testing, detailed pump inspections, regularly scheduled component replacements. The new PLC-driven systems (through rehabilitation replacements or retrofit bypass) are essential to being able to monitor and analyze lift station operation parameters.
• Assess feasibility of replacing “service main” installations (multi-service sewer lines.)
• Assess feasibility of replacing or lining old, vitrified clay (VCP) mains susceptible to root intrusion and pipe collapse.
• Continue asset management program; this is a very important process.
Attachments
A - Annual Presentation_Wastewater Systems