San Jose-Santa Clara Regional Wastewater Facility Yard Piping Condition Assessment

Project Description 

V&A performed condition assessments of process piping in support of the Yard Piping and Road Improvements Project (Project) at the San Jose-Santa Clara Regional Wastewater Facility (RWF). The purpose of the assessments was to obtain physical condition data on buried piping assets so that rehabilitation design and prioritization can be performed by the City of San Jose’s Environmental Services Department (City) and Black & Veatch Corporation (Black & Veatch), who serves as the Owner’s Advisor (OA) for the Project. V&A also helped establish a baseline for data collection, interpretation, and reporting for future Yard Piping assessments on the Project. 

Condition assessment methods used to evaluate the piping included visual assessment with photo and video documentation, closed circuit television video (CCTV) with hydro-jet cleaning, lining assessment, concrete sounding, concrete penetration measurements, surface concrete pH testing, surface penetrating radar, and concrete coring. Due to the crown corrosion from biogenic corrosion that was observed, V&A also took dimensional measurements to help quantify the extent of damage.

The results of the field investigation were analyzed and utilized to develop overall pipe condition ratings. Pipe condition ratings were based on a scale between 1 and 5, with 1 being new or excellent condition and 5 being failed or imminent failure. These ratings were used to estimate the remaining service life of the piping as well as to help prioritize repair and rehabilitation needs.

Assessment, Design and/or Construction Challenges and Solutions

V&A prepared a safety plan to mitigate risks and to outline procedures to be implemented during confined space entry work related to the Yard Piping Condition Assessment at the RWF. As with all projects, safety is of the highest priority and is an integral part of our work. V&A’s confined space trained engineers conducted the field investigations with onsite confined space entry and rescue support from Lee & Associates Rescue, Inc. (LAR) and/or Jamison Engineering Contractors, Inc. (Jamison).

In order to ensure consistent data collection and reporting on the project going forward, V&A worked closely with the Black & Veatch and the City to develop a pipe rating index system based on the National Association of Sewer Service Companies (NASSCO) Pipeline Assessment and Certification Program (PACP). The pipe rating index system allowed V&A to assign defect grades and overall pipe ratings to individual pipe segments, and ultimately correlate the ratings to an estimated remaining service life.

The Way to Effective Odor Control

Chocolate chip cookies. Fresh cut grass. The ocean breeze. Each of these scents likely invokes a specific feeling or memory. Neuroscience tells us that the sense of smell is strongly linked to memory and emotion, probably more than any of our other senses. Our perception of odors as good or bad depends as much, if not more, on how we feel about past events associated with the memories these odors trigger as it does on what it actually smells like.

Odor complaints can often be one of the most perplexing problems when operating a wastewater system, due to their subjective nature and seemingly unpredictable pattern. A positive experience in how the odor complaints are handled will leave a lasting impression on stakeholders and operators alike. Having a well-structured procedure for documenting and investigating odor complaints is necessary to effectively manage these issues.

There are a number of considerations that may influence the scope and size of an odor control strategy, including regulatory requirements, corrosion concerns, and the desire to be a good neighbor. Clearly defining the goals of an odor control program is key to developing the most straightforward approach to mitigating odor emissions. Seemingly unrelated odor and corrosion issues are often influenced by a few key contributors that result in systemwide problems. Identifying the most effective odor control strategy requires a prioritized approach to eliminating the low hanging fruit and mitigating odor emissions across the entire system.

V&A uses a variety of tools to identify and characterize odor issues, including hydrogen sulfide and differential pressure monitoring, odor sampling, and ventilation and air dispersion modeling. Hydrogen sulfide is one of the most common parameters evaluated as it a good indicator of the source of both odor and corrosion issues. It is easily monitored, influences the technology selection and operating costs of most odor control solutions, and its generation rate can be incorporated into hydraulic models to compare alternative solutions and determine the impact of future infrastructure changes on the systemwide odor conditions.

Quantifying odor complaints beyond subjective terms such as “terrible” or “unbearable” is important to monitor the effectiveness of the odor control strategy. Olfactometry measurements provide a repeatable and quantifiable basis for investigating odor complaints and comparing the relative “strength” of different odor sources. Once the odor concentration is known for a given odor source, V&A uses air dispersion modeling to determine the likelihood that odor emissions are migrating offsite, understand how future infrastructure upgrades may change the odor conditions, and identify the required odor removal performance to meet the odor control objectives.

Vapor phase odor control is an effective means of treating odors from a variety of sources in a centralized system, even in large collection systems. Using the latest advances in biological odor control, high hydrogen sulfide and odor loading sources can be effectively treated in a sustainable manner with minimal operating costs and little or no chemicals. V&A uses sewer ventilation modeling to determine the capacity for airflow within collection systems, and fan testing to determine the viability of vapor phase treatment systems. Combining hydrogen sulfide and differential pressure monitoring, fan testing involves extracting known quantities of air to simulate the effects of a permanent odor control facility. V&A has used these methods to effectively size and locate vapor phase odor control facilities within wastewater collection systems from 100 cfm to over 40,000 cfm in capacity.

It is important to remember that there is not always a clear path to effectively addressing every odor complaint in a wastewater system. It often requires an iterative approach of identifying the most significant contributors, implementing the appropriate solutions, and evaluating how effective these solutions are at meeting the odor control goals. A comprehensive odor control strategy that includes investigation, evaluation, and implementation will ensure that you are headed in the right direction and enable you to set realistic expectations for your stakeholders within the available funding mechanisms.

What is that smell?

Let’s get into the weeds on the process of quantifying the relative strength of ambient air. Field olfactometry is a reliable method of measurement using a portable olfactometer, informally referred to as a “scentometer.” V&A recently used the Nasal Ranger® Field Olfactometer as part of a wastewater odor control evaluation. The Nasal Ranger “creates a calibrated series of discrete dilutions by mixing the odorous ambient air with odor-free (carbon) filtered air”1. The odor strength is quantified in terms of “Dilution-to-Threshold” (D/T) ratios, a measure of the number of dilutions required until the sample no longer has any detectable odor. Field olfactometers provide a scientific, repeatable method for determining background odor concentrations, investigating odor complaints and documenting the severity of specific events, prioritizing odor sources for detailed analysis, and verifying the assumptions used in odor dispersion modeling.

Field Olfactometer

1 Nasal Ranger® Field Olfactometer Operation Manual, St. Croix Sensory, 2008.



Back to the Future 1978

V&A Mission: To dedicate our expertise to achieve a better world through resilient and sustainable civil infrastructure.

V&A opened its doors 39 years ago in 1978 and our mission has remained the same from our early beginnings. We recently spent some time looking through our archives and found several newspaper articles (see below).  In those days, the newspaper would write about local council meetings and report on projects that were taking place.. Our first office was in Oakland, so many projects were rooted in that area. For example in 1982 we were part of the renovation of the Old Alvarado Hotel, which ultimately became our office. Other projects include the Golden Gate District Project, which included the Golden Gate Bridge, Highway and Transportation District  where we completed a corrosion investigation at the Larkspur Ferry Terminal. For the Cross Valley Pipelines project, we were a subconsultant to George S. Nolte and Associates and Ameron at the Tracy Plant  where we performed in-plant inspection services for the production of 78 inch prestressed concrete piping. The manufacturing of the pipes included many special elbows, tees, outlets and special fittings. The coating system for the fittings included both fusion epoxy and cement mortar. The Cross Valley Pipeline Phase II is one of five projects that formed a new water transmission system for the Santa Clara Valley Water District.

The Archives brought to mind a host of projects that helped define a young company and improved the community we called home.

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Our pledge for World Kindness Day, November 13th

V&A Consulting Engineers is celebrating 39 years working with municipalities and private industry to maintain the life of water, wastewater, and transit systems. We are committed to sustaining our community's infrastructure. World Kindness Day is November 13th, and in celebration of our 39 years, our team is pledging to accomplish 39 (or more) Acts of Kindness before the anniversary. These include individual gestures as well as team efforts. We’ve put together a list of possibilities ranging from running errands for an over-whelmed neighbor to planting a tree or being an encouraging ear for a co-worker. We are all keeping track of our efforts and will share them on November 13th. We’re happy to share our list of suggestions, so just drop us an email if you’d like to join the movement.  

Individual Acts of Kindness (partial list)

1. Send an encouraging email. - Short and sweet can make someone’s day

2. Volunteer to run an errand for a neighbor or relative if they are under-the-weather or over-whelmed.

3. Go to Goodwill and leave a $5 on a shelf in the toy aisle. Some child and mom will be thrilled at the find.

4. Plant a tree. It’s good for our environment and life.

5. If you see your neighbor forgot trash day - wheel out the trash bins.

6. Complain less - Remaining positive in a negative situation makes you a leader.

7. Buy lemonade from a kids lemonade stand. Leave a big tip!

8. Animal shelters always need blankets and towels. If you have any old ones, call and see where to drop them off.

9. Animal shelters also need food and treats - buy a few cans or bag of dog food and drop them off.

10. Make a handmade card and surprise someone with something unexpected.

11. Bring reusable bags to the grocery store.

12. Make an effort to learn something new about a co-worker.

Group Acts of Kindness

Create opportunities to give acts of kindness in small or large groups. Here are a couple examples. Look for opportunities in your community, walks, runs, drives etc.

1. Hold a Teddy Bear drive. Pick a date to collect. Then donate to a hospital, police station or fire department for children in need.

2. Breast Cancer Month - October

Race for the Cure. https://ww5.komen.org - There are races in San Francisco, San Diego and Houston if interested.

3. Choc Hospital “Walk in the Park” presented by Disneyland. August 26, 2018. https://www.chocwalk.org

The CHOC Walk in the Park presented by the Disneyland® Resort brings the community together for one single goal – to raise funds for health care programs, education and research for Southern California’s kids. With your favorite Disney® characters cheering you on, celebrating children has never been so fun! Fundraising minimum $95/person. There are also specially priced Park tickets - $61. one day, one park or $87 one day, both parks.

4. Toys for Tots - at Christmas. https://www.toysfortots.org Local drives in your area.

#bethespark

Permanent Canal Closures & Pump Stations Project

V&A Consulting Engineers was retained by Stantec to provide corrosion engineering services for the United States Army Corps of Engineers’ Permanent Canal Closures & Pump Stations Project located in New Orleans, Louisiana. The project included the design and construction of three pump stations intended to discharge water from the city into Lake Pontchartrain in the event of flooding. A steel bulkhead structure was installed at each pump station to convey water from existing canals to the pump stations; the bulkhead structures consisted of multiple face and drag sheet piles driven to a depth of approximately 80-feet. Due to the corrosive environment at the project locations, cathodic protection (CP) systems were required to mitigate corrosion of the bulkheads.

V&A designed three cathodic protection (CP) systems for each pump station bulkhead; a galvanic anode CP system for the exterior water side of the bulkhead, a galvanic anode CP system for the exterior soil side of the bulkhead, and an impressed current CP system for the interior soil side of the bulkhead. CP system design calculations, details, and specifications were submitted for each CP system. Once the installation of the systems was complete, V&A performed a site visit to each project location to activate, test, and adjust the CP systems to ensure corrosion of the bulkheads was mitigated per NACE International SP-0169 criteria for adequate corrosion control. A report was submitted to present the data collected during the field testing and to provide recommendations for future operations and maintenance of the CP systems.