The stink that all humans are familiar with

You know the smell the second you smell it.  Sewer stink.  Poop aromas in the air. Outside, in the open.  Definitely not something you want to enjoy whilst on your deck sipping wine, listening to the birds chirping their love songs. Or while walking your dog down the greenway along a sewer line (usually the lowest topographical elevation around a city).  Or while driving in your car, even when your windows are closed.

This brings me to two impactful experiences I’ve had with sewer stink.  One of them is from my youth, growing up in Venezuela, and the other is from the early 1990’s when I lived in Charlotte NC.

A direct path from toilet to lake: a true story

In the 1970’s in Cabimas Venezuela, when you flushed your toilet, all of that excrement would make it’s way to Lake Maracaibo with little to no treatment.  Yes, it would go to a central processing “plant”, but the treatment plant didn’t actually treat any of the incoming waste streams.  Or if it did, it was minimal, perhaps merely removing most of the solid stuff.  And guess where the plant’s outfall is?  Yup…Lake Maracaibo. Direct discharge of barely treated human waste at an unpopulated location near the bridge from Cabimas to Maracaibo.

At one time, prior to the late 1960’s/early 70s, Lake Maracaibo had crystal clear water (with the occassional oil slick due to this lake’s massive oil operations).  I know this because I swam in that lake when I was a kid.  My great gramdmother had a house right on the water, with a pier that you could go out on and jump into the lake. But by 1973 or so, those crystal clear waters gave way to frothy pea-soup green waters, replete with enormous amounts of algal blooms that caused all kinds of problems…even the occassional fish kill because of oxygen-starved water.  It’s a miracle that that lake hasn’t already died.  The only thing saving that lake are all the massive rivers feeding into it from the south, and the inlet to the ocean on the north.

The root cause of the algae infestation in that lake are nitrogen and phosphorus loading from human excrement.  Those problems didn’t come from the oil industry, which had its occassional oil spill on the lake…it came from urban development, and more specifically, the lack of infrastructure to treat all the human waste generated from that urban growth.  The easiest solution was to just do the minimum, discharge it into that massive lake and hope that dilution would take care of it.

But it didn’t.  It turned the lake green. No one could swim in that lake anymore, for fear of getting skin sores and who knows what.  Fish caught in that lake were now suspect…would you eat one? Not me.  Fishermen had to now go further out to catch fish.

And the smell?  Yea, it was nasty, particularly as you approached the 10-km bridge spanning across the lake from Cabimas to Maracaibo, on the Cabimas (east) side.  Even with the air conditioner in the car on full blast, recirculating the indoor cabin air, and all the windows closed, you could still smell the shit for a few kilometers while driving west on the massive bridge.

And it looks like this human waste issue I experienced myself decades ago is still a problem today (in 2024), as evidenced by the Associated Press article published Aug 15, 2023 (gif below).  In Lake Maracaibo’s case, the smelly odors are the least of their worries.  A dying lake is something entirely different, and until proper wastewater treatment is implemented at a massive scale, the odds of that lake surviving continue to dwindle.


Pineville NC: A smelly ‘Charlotte ‘burb in 1993

Around late 1993, I moved from Knoxville TN to the south end of Charlotte, NC. Specifically, to the Pineville NC area just south of Charlotte. Each morning, as I drove north on Park Road, the sewer stench would infiltrate into my car, even with the windows rolled up. This was every.single.morning…like clockwork. Clearly, the McAlpine wastewater treatment plant managing Pineville’s sewage waste had an odor problem back then. To this day I still remember that stench every morning.

But it appears like that may be a thing of the past, as odor control mitigation was finally implemented at the McAlpine Creek wastewater treatment plant.


Tackling odor control at the source

As should be evident, treating raw sewage matters.  And treating the hydrogen sulfide odors emanating from it also matters.  There are various ways to treat H2S odor, and Source Technologies, LLC (SourceTech) is expert at this.  One way is through chemistry.  SourceTech’s chemical mixture and exact process are proprietary, but we can at least mention the mechanics of one of their processes.  Take a look at the simple schematic below.  To summarize, a specific chemical mixture is metered into the wastewater processing tanks at a given rate based on various variables such as retention time, tank volume, etc.  A chemical reaction occurs, stripping the sulfide from the H2S molecules, and voilá! No more odor.

Documenting and tracking using spreadsheets

Prior to the use of XForms, SourceTech would track catalyst and oxidant settings, feedrates, and tank volumes in a spreadsheet.  Dissolved sulfide and H2S readings were also tracked in a spreadsheet.  The information gathered in these sheets would be used for reporting purposes, documenting on-site activities that would later be used for billing purposes, and for general trend analysis at project sites.  Dissolved sulfide and H2S readings would be used to tweak the chemcial formula and feed rates,  and predictions would also be estimated as to when the chemical injection tanks would run low, so that they could send a field crew to refill them and conduct O&M.

Here’s one of the spreadsheets that SourceTech used.

Pain points of spreadsheet tracking

Some pain points sourceTech experienced when using standalone spreadsheets were fairly obvious and common:

  • Individual spreadsheet files circulating around the organization
  • The data embedded inside each sheet is not easily aggregated into a common location
  • Transfer from paper forms to spreadsheets *double entry and potential transcription errors)

Other pain points were less obvious:

  • Formulas inside individual spreadsheets can have errors (unless fields are locked down)
  • Searching and sorting through dozens of individual spreadsheets just to find something specific can be problematic and time-consuming
  • Can’t attach photos to a spreadsheet

Improving their field forms

One of the very first steps we did as a team effort (SourceTech + XForms) was to evaluate the existing spreadsheet-based forms and figure out how best to replace these with a digital system. While sometimes migrating an analog form to digital is straightforward, with a near 1:1 direct transposition of fields from a paper-based form to a digital equivalent, it’s best to first evaluate the original form and see where things can be reduced, removed, and automated.  For example, some basic questions we reviewed about their existing paper-based forms:

  • Is all the information requested on a particular form absolutely necessary? If not, which fields can be eliminated from the form?
  • Do you use all the information requested on the form? If there are some pieces of information that are virtually never used or analyzed, then leave them out and maybe put them on a different form template that will be used less frequently.
  • Can some text fields that are populated with common values be replaced with listboxes, so that the field tech can simply select one instead of type into the field?
  • Can some fields auto-populate with default values, so that the field tech doesn’t have to enter a value for that field most of the time?
  • If the form is really long, is there a natural break point in the form, so that the long form can be split into 2 or more shorter forms?
  • Can optional fields be grouped into a section that can be collapsed and almost hidden, so that most of the time the field tech doesn’t even have to scroll through fields that are not applicable in a particular field event?

The above questions gave rise to modifying their new digital forms multiple times over a period of several months, where the digital form templates were studied, designed, tested on actual projects, and then updated based on field tech feedback.  Some templates were scrapped, some were merged together, and some were tweaked many times.

The surviving form templates were the ones that:

  • field techs embraced and actually used because of their simplicity, and

  • provided actionable information and data to project managers and admin staff reviewing the data collected.

Here’s a gif of one of their forms.


Back-office benefits

Quick access to data

Take a look at the gif below. Within seconds a SourceTech projct manager can drill down and view exactly what they need, including pictures taken during the field event.


They can print their completed field forms to PDF:

View photos taken in a photo gallery:

And even view a map of where the field forms were initiated:

If they need more analytics power, they can export directly to Excel for further data processing:

And the right people are notified automatically whenever a new form is submitted into the system:


Future enhancements to SourceTech’s solution

Alerting field techs of predicted low tank volumes

A future enhancement of their system will be to automatically predict “days to empty” for specific tanks at specific sites and then automatically alert the regional manager, field tech, and VP of operations at 30 days until empty and then a final alert at 15 days until empty.  This feature will be added with the help of a 3rd party integration tool called  

Extending the power of XForms through integrations

Another future improvement to the SourceTech + XForms solution is to automatically upload submitted forms and photos to their cloud-based document repository.  This means that as soon as a field tech completes and submits a form—even while on a project site—the PDF of this form, and any accompanying photos will automatically be pushed up to SourceTech’s document storage system.  Information about this type of integration can be found here:


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