Monthly Blog

On March 21st, members of the RMWEA/RMSAWWA Lab Practices
Committee(LPC) and RMWQAA toured the wastewater treatment plant at the Lockheed Martin Space Systems, Waterton Canyon located in Littleton, Colorado. This treatment plant serves the 6200-acre facility with a rich history of industrial use. The site was first constructed in the mid 1950’s to build the Titan I intercontinental ballistic missile. Since the initial build, the company had experienced several mergers and different focuses and has been known as Lockheed Martin since 1997. 

Over the years, the plant has manufactured hundreds of rockets designed to carry missiles, and communications satellites into space.  Crafts such as the Titan, Gemini, Viking, Voyager, and Cassini were all built at the Waterton Canyon facility.  Waterton Canyon was chosen specifically because the natural geology of the area provided more security and noise control than other sites.  In fact, the location tops a 1,700-foot-deep bedrock formation that isolates it from even the smallest seismic movement and provides the ultimate environment for testing the stability of various systems.

Early years of rocket launch testing contaminated the soil and groundwater with rocket fuel and manufacturing chemicals.  The EPA declared it a Superfund site in 1989, however, this designation was soon removed.  Initial clean-up efforts included removal of contaminated soil, wells, and solid waste.  Decades later the main contaminant remaining in the groundwater is N-nitrosodimethylamine (NDMA), which is a breakdown product of hydrazine rocket fuel. Lockheed’s industrial wastewater treatment plant is responsible for treating the groundwater as well as production waste from space component manufacturing processes.  Domestic waste is collected and piped to South Platte Water Renewal Partners (previously known as Littleton/Englewood Wastewater Treatment Plant) where it is treated and discharged into segment 6a of the South Platte River.

The NDMA contaminated groundwater treatment has been going on continually for the past 20 years. Luckily, the geography of the area funnels groundwater into two main channels making it easy to reclaim all of it for treatment.  NDMA is treated via UV Photolysis where it’s degraded using high levels of UV irradiation.  The Nitrogen bonds are broken leaving NO and (CH3-N=CH2).  The NO then gets oxidized into nitrite and then nitrate.  The dimethylamine oxidizes to form bicarbonate.  The UV bulbs are similar to the bulbs used in domestic wastewater plants, but instead of having a group of bulbs in a grid, only one very high-powered bulb is used. 

Initial levels of NDMA in the groundwater were around 300 ppb. After 20 years of continual treatment, the levels have dropped to about half, and through treatment, they are able to meet their permit limit for NDMA.

Other waste streams contain high levels of chromium and zinc from manufacturing or washing processes.  Aluminum is etched off of casings of crafts to minimize the weight and fuel it takes to launch.  Chromium plating is used to prevent oxidation.  The metals are treated using hydroxide precipitation, followed by polymer flocculation. The sludge is then dewatered with a sludge press and dried for disposal. The final effluent water goes through sand filtration, Nitrite oxidation, carbon feed, granular activated carbon (GAC), ion exchange, and final pH adjustment.  

The industrial wastewater treatment plant discharges just upstream of Chatfield Reservoir, which requires discharges to meet stringent fishery, recreation, and drinking water standards outlined in Control Regulation Reg 73 that can be found here:    https://www.colorado.gov/pacific/sites/default/files/73_2009%2803%29header.pdf   

Lockheed Martin hasn’t had a permit violation for decades and has actively participated in the Chatfield Watershed Authority. The tour was very informative and interesting.  Although we didn’t get to tour any of the rest of the top-secret, high-security site, we did see the hillside that they once launched rockets into as well as a peek at the new $350 million dollar Gateway Center right next door to the plant.  You can read more about that here:  https://www.lockheedmartin.com/en-us/capabilities/space/gateway-center.html

Michelle Neilson, Water Quality Technician, has been with Metro Wastewater for 8.5 years.  She has a B.S. in Chemistry, and has 19 years of experience in the Environmental field.  Michelle has worked for USGS, contract laboratories, and several municipal wastewater and drinking water labs prior to Metro Wastewater.

PFASs or per- and polyfluoroalkyl substances have become a growing concern over the last decade due to widespread use and persistence in the environment and in the human body. According to the ATSDR (Agency for Toxic Substances and Disease Registry), PFAS are man-made chemicals that have been used in industry and consumer products worldwide since the 1950s. The most common types of PFAS include perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), however, there are many other forms which are not studied as well and used throughout the world.  They can be found in non-stick cookware, water repellent clothing, stain resistant fabrics and carpets, firefighting foams, and products resistant to grease, water, and oil. The widespread production and use of PFAS contributes to its ubiquity not only in the environment, but also leads to its accumulation and persistence in the human body.

Environmental exposure to PFAS could occur through multiple methods from contact with the manufacturing process, usage, and disposal of PFAS products. For example, surface water or groundwater and the surrounding soil becoming contaminated after receiving run-off in areas where firefighting foam was used. According to the EPA, human exposure can occur through daily usage of popular consumer products such as cookware, stain repellants, and even pizza boxes. A major concern with PFAS exposure is its persistence and ability to stay in the environment and in living organisms for a long period of time. As a result of repeated exposure, the amount of chemical in the bodies of humans and animals alike can accumulate and lead to adverse health effects.

Researchers have been studying the adverse health effects in animal models to better understand how these chemicals cause toxicity and what organ systems are being affected. Studies indicate that the PFAS can disrupt endocrine activity, reduce immune function, and can cause adverse effects on multiple organs including the liver, kidneys, and pancreas (NIH, 2019). Epidemiological studies with humans, though limited, have shown an increase in cholesterol levels, cancer, and thyroid hormone disruption (EPA, 2019). Although more research is needed to fully understand the health risks and impacts of PFAS, actions have been taken to limit the exposure to these chemicals.

The EPA lowered the non-binding health advisory limit for some PFAS compounds found in public water systems. However, because of the growing concern that these chemicals may cause adverse effects to human health at lower levels, further action was taken to reduce exposure in some states. In Fountain, Colorado, the EPA announced the first-ever comprehensive nationwide PFAS action plan. The plan consists of expanding PFAS monitoring in the environment, enhancing scientific research for addressing PFAS by developing new analytical methods and tools, and clarifying clean up strategies. Furthermore, two chemical classes of PFAS have been phased out of industry in the United States, PFOA and PFOS, and the EPA is working to list these chemicals as hazardous substances under the Superfund Program (ATSDR, 2018). Future strategies and regulations include recommendations in the clean-up of the persisting PFOA and PFOS levels in groundwater and expanding limitations to other chemical classes of PFAS.

References:

Agency for Toxic Substances and Disease Registry (2018 January 10). Per- and polyfluoroalkyl substances (PFAS) and your health. Retrieved from https://www.atsdr.cdc.gov/pfas/overview.html

Brady, J., Hurdle, J. Phillips, S. (2019 February 14). EPA says it plans to limit toxic PFAS chemicals, but not soon enough for critics. Retrieved from https://www.npr.org/2019/02/14/694660716/epa-says-it-will-regulate-toxic-pfas-chemicals-but-not-soon-enough-for-critics

National Institute of Environmental Health Sciences (2019, March 8). Retrieved from https://www.niehs.nih.gov/health/topics/agents/pfc/index.cfm

United States Environmental Protection Agency (2019 February 13). News release: EPA to announce first-ever comprehensive nationwide PFAS action plan in Fountain, Colorado. Retrieved from https://www.epa.gov/newsreleases/epa-announce-first-ever-comprehensive-nationwide-pfas-action-plan-fountain-colorado

United States Environmental Protection Agency. Basic Information on PFAS. Retrieved from https://www.epa.gov/pfas/basic-information-pfas#main-content

Ashley Romero is the Laboratory Manager at GEI Consultants, Inc. and has a background in ecotoxicology.

February was a busy month for the RMWQAA with a brewery tour and participation in the Metropolitan State University of Denver's Water Career Fair. The Breckenridge Brewery’s Littleton campus hosted a group of nearly 30 analysts for a FREE, fun-filled tour of the beautiful brewery and tasting room. After having all our questions answered by the tour guide and laboratory guru, we wrapped up in the restaurant with a rousing game of telephone. Just as much fun as elementary school with pink pigs flying!

Five RMWQAA members manned a booth at Metro’s water career fair on Tuesday February 26th. RMWQAA flyers and handouts summarizing other resources for water careers were provided to attendees. Many students stopped by the fair to chat with our RMWQAA leaders about their jobs in the water field, promoting the value of water careers.

Don’t miss out on future RMWQAA and RMWEA-LPC sponsored events! There are still open spots in the upcoming Lockheed Martin Tour. Sign up today!!

To kick off 2019, RMWQAA was pleased to sponsor a tour of the ERA lab in Golden, Colorado. Tucked up aside one of the many beautiful hills that dot the Front range, about 18 people were treated to an inside look at a premier proficiency testing laboratory. ERA was founded in 1977 in Chicago, Illinois by a pair of cousins who were also prominent members with Test America and Colorado Analytical. ERA was acquired in 2006 by Waters Corp, the worldwide leader in liquid chromatography, mass spec, and thermal analyses. Waters Corp now houses the lab we were visiting on the 9^th of January, where they have been located since 2011.

After a quick introduction to our tour guides Daniel, Colleen, and Curtis and an emergency exit protocol reminder, we were off in groups of 5 or 6 to check out the lab and surrounding offices. Being the largest proficiency testing company in the U.S. requires quite a large lab and a hefty workforce to go with it. This was apparent when we were shown to the laboratory, where nearly half of ERA’s 86 employees work. The lab is split into sections, with an inorganic side and an organics side. The inorganic side is responsible for much of the proficiency testing and quality control work. They also run IC and mercury analyses, as well as TOC and conductivity for ultra pure water systems. To the side and in a separate room is where they work with their soil samples. It was interesting to find out later on that they typically collect enough soil to work with the same batch for 6-7 years.

On the opposite site of the lab we found organics analyses being performed. These included radio-chem testing, gas and liquid chromatography, and a separate room for microbiological testing. This side of the lab was also where Waters Corp employees did work with their standards and reagents. Just outside the laboratory we found the shipping department, a highly organized and well-oiled machine of a workforce. Even in January they were already prepared to ship hundreds of orders and prepare thousands

 more! I couldn’t exactly pinpoint their method of organization, but it was clear they knew what they were doing and where every item could be found!

As we looped back towards the start of the tour, we were introduced to the various customer service teams at ERA. The IT department consisted of 5 individuals, highlighted by Harlan, who was responsible for creating the eDATA platform that ERA and its customers use to analyze data. This was implemented in 2015 and is an impressive piece of programming worth digging into! Next to the IT department was a group of 8 people who handle the large volume of calls and e-mails received nationally and internationally. Between them they typically take over 200 calls per day! The remaining positions taken in the customer service department of ERA were the 3 individuals who communicate with state and regulatory bodies, check data for accuracy, and handle reports. In 2014 Waters ERA established a 2-day turn around for final study reports following the end of a PT run. These three people manage to double check reports and data for errors AND get the reports sent out quickly. Clearly the 12-15 years of experience, on average, between the three of them has produced some high quality work!

The tour concluded with a walk through the main room, where it was pointed out that each of the conference rooms were named for elements. Meeting in the Hydrogen room, ASAP! Once we settled into the original meeting room with some cookies to snack on, we were treated to a solid Q&A session with five prominent members of the ERA staff. Between Tom, Curtis, Mike, Tom, and Brian we attempted to gain all the insight from the decades of experience standing before us. While we weren’t able to acquire the answers to this years DMRQA’s (sorry all), we did find out a couple of interesting bits of information:

              

-Most, if not all of the customer service department teams also have Biology or

Chemistry degrees, and typically everyone began work in a lab prior to joining their team.

        -ERA handles over 600,000 individual data points each year.

        -If you are looking to receive a proficiency test for a certain analyte and it isn’t available, chances are not enough labs are looking to participate in the same test. It takes 15-20 labs in order for ERA to develop enough quality data to permit sending proficiency testing materials for a certain test. Some labs running the more obscure analyses may have to look elsewhere or talk some other labs into requesting some proficiency testing.

        -Ever wonder what the most failed DMRQA analysis is? Surprisingly it’s pH!! Due to the sheer volume of data points taken, the high confidence level on QC for pH correlates to a range much smaller than other tests. Flip that and look at the least failed DMRQA: BOD! With the widest range of acceptable values, this test tends to hit most often, though that still doesn’t seem to make the BOD setup any less stressful.

Thanks to all of the people involved in putting this tour together as well as those employed by ERA in helping create accurate QC and PT data! Personally, I walked away with a great amount of respect for the process that goes into creating our proficiency tests that we rely on to prove our accuracy to the state, and really enjoyed touring Waters’ ERA facility! They also sent us home with a sweet color changing mug, some always needed pens, and a flash drive for all those data points!

*Photos were not allowed to be taken in the lab, my apologies for the lack of pictures to go with the newsletter*

Tyler Eldridge has a BA in Biology from CSU. He is a Water Quality Analyst for the City of Greeley, volunteers for the RMWQAA, and maintains the RMWQAA website.

Dissolved Organic Carbon is one of the key water quality components affecting aluminum toxicity and the EPA has taken DOC into account in the newest version of the aluminum criteria. The EPA read through hundreds of comments on the draft aluminum criteria and has made significant improvements over the previous 1988 version that reflect the newest science. The new criteria was only published this month and it will be a while before Colorado and other states fully adopt the new criteria. The EPA has created a tool to help dischargers calculate the aluminum criteria for their site. All you need are the pH, hardness, and DOC concentrations for the receiving water and you can find out the expected new aluminum criteria for your site. So get out there and collect your data now so you can be prepared when the new criteria are implemented in your state. Click here to read the full aluminum criteria document.

These days drones are everywhere in the news….drones surveying landscapes, drones taking pictures, even drones delivering pizza. At a recent conference, drones were again at the center of the conversation, but this time, the talk was about drones collecting water samples.

 

For anyone who has spent a day launching a boat, and fighting waves, seagulls, and other hazards, the idea of drones doing all that work for you sounds pretty good. While there are numerous benefits to drone sampling, there are significant costs associated with it too.

 

Let’s start with the positives. Drones can provide an excellent tool for reaching hard to access waterbodies. Much of the drone water sampling currently is at pit lakes at mine sites where access to the water’s edge is risky. Drones allow personnel to work safely, well away from the water’s surface. 

 

Another benefit is the ability to collect samples at numerous depths using Kemmerer or Van Dorn-type samplers. This allows the sampler to get the same quality data from various depths without being in unsafe conditions. Drones can even be fitted with probes that collect a full suite of standard water column profile data such as depth, pH, temperature, and conductivity.

 

Even though the upfront cost of a drone sampling system would be high, in the long run, the savings would likely be made up in personnel costs. Typically, launching a boat requires a minimum of two people for safety reasons, and unless the boat is permanently in the water, getting the boat to the site, launching, and all the required sampling can be quite time consuming. Drones can save a significant amount of time by simplifying the entire sampling process.

 

Drones aren’t for everyone. They do require licensed pilots and many flying restrictions such as keeping the drone within your line of sight and avoiding certain airspace, makes them infeasible for some sites. Battery power is also still a limiting factor. The standard flight time when carrying heavy loads of water can be as short as 15 minutes, meaning numerous sites may not be sampled in a single day without battery replacement or recharging.

 

As the temperatures drop, you might be imagining piloting a drone from the warmth of your car, rather than sitting in a cold boat, hoping you don’t get splashed. Unfortunately, if high winds or fog are present, the drone may be grounded and you’ll be stuck sampling the old fashioned way. Despite the drawbacks, drones are allowing samplers to work in much safer conditions than ever before. As long as researchers continue to think up new uses for drones, we may one day be able to stay cozy warm while lake sampling is still getting done.

 

Natalie Love is the Laboratory Director at GEI Consultants, Inc. GEI conducts Whole Effluent Toxicity (WET) Testing, low-level nutrient analysis, and benthic macroinvertebrate identifications. She lives in Denver with her husband, 2 daughters, and mastiff.

This is an excerpt from an article published by the Associated Press

 

Click the link for access to the full article:

https://www.usnews.com/news/best-states/new-mexico/articles/2018-10-03/mushrooms-could-help-clean-toxic-groundwater-in-new-mexico

 

 

This excerpt was taken from www.USnews.com and reprinted under the Fair Use act of 2007

 

Information from: The Santa Fe New Mexican, http://www.santafenewmexican.com

 

Water conservationists and a Native American women's advocacy group believe they've found a potential solution to a massive, decades-old underground plume of toxic chromium that likely has spread from property owned by Los Alamos National Laboratory to San Ildefonso Pueblo land.

 

The key ingredient? Mushrooms. They want the lab to give their fungi-based idea a try.

 

At an upcoming meeting, the nonprofit Tewa Women United and Communities for Clean Water will try to convince lab officials to start a pilot project to test whether a bioremediation technique based on mushrooms could help decontaminate the aquifer of hexavalent chromium that lab workers over several decades dumped into a canyon from cooling towers at an old power plant.

 

It may sound far-fetched, but advocates say the technique, called mycoremediation, could be healthier for the environment and less costly than efforts the lab is currently using to treat contaminated water pumped out of the plume. The lab is testing other remediation methods as well, such as pumping molasses and bacteria into the plume to convert the highly carcinogenic chromium-6 to chromium-3, which is far less toxic.

 

"Conventional remediation strategies are inherently harmful to a very fragile ecosystem," said Kaitlin Bryson, an Albuquerque-based artist and organic farmer who is helping spearhead the mycoremediation proposal.  Bryson, 30, said the idea is in its infancy, and she's not sure exactly how many mushrooms it would take to completely restore the aquifer.  "I really can't conceptualize," she said.  The group plans to pitch the idea during a public hearing in Los Alamos in early November on a state discharge permit for the lab. The groups contend the permit was approved three years ago without public input.  "It's really not a crazy concept," said Peter McCoy, a Portland, Oregon-based mycologist, a scientist who studies fungus, who is helping Bryson with the proposal.

 

McCoy has experimented with mushrooms for about 17 years and has been leading smaller-scale mycoremediation projects for four years. The results can be significant, he said.  The technique uses mycelium, the vegetative body of a fungus, which acts as a magnet to extract heavy metals from soil and water.  The first step is to grow molds in a material such as agar, a jelly-like substance found in some types of seaweed. The substance is then inoculated with mycelium and grows. The end result is a mycelial "brick" or "bead," which is used to strip away toxic materials, advocates say.

 

The method has been used to break down diesel fuel, harmful bacteria and even diapers, according to studies by Paul Stamets, a mycologist who has secured an Environmental Protection Agency contract to research mycoremediation.

 

The strategy also has been used in the Ecuadorian Amazon, where Chevron is accused of dumping billions of gallons of oil-drilling waste into unlined pits.  McCoy sees the chromium plume project as an opportunity to advance the science. "If we are able to move forward, this would be a great proving ground for this technology," he said.  "It's really a no-brainer," said Bryson.

 

She led a mycoremediation workshop in April and again earlier this month at the Regeneration Fest: Youth Water Protectors Gathering in Española, where participants explored ways to care for their communities, land and water. She hopes to hold similar workshops in the future.  Bryson envisions a community remediation effort in which homemade mycelial bricks or beads are placed at a contamination site as part of an art-like installation.

 

Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

 

Analysts from Northglenn, Broomfield, Metro, and Aurora display their molecule string art made at the Summer Social 2018

 

What is Networking?  Jockeying for position for a new job?  Hob nobbing with more “important” people?  Memorizing the names and personal addresses of 50 people in a room?  Maybe it’s not as hard as it seems.  The best way to network for one person may be the complete opposite for another.  This is more of a discussion around why networking is even a thing and how to approach it with a healthy goal in mind.  For many of us lab folks, the idea of networking can be exhausting and really freak us out.  So, why should we get out of the comfort zone of the lab to mix and mingle with other lab people?  Analytical skills don’t always cross-over to people skills but getting to know people in other labs can be important for many different reasons.  It can lead to:

• Sharing of ideas. What better way to learn about a new process, method, or way of doing things than in a casual setting over a drink or bite to eat?

• Solving problems. Our field is not Top Secret. Labs are often reluctant to tell others when things are going wrong, but in this community, people want to help and by opening up and sharing issues you are having in your lab, you can learn other options to solve your problems.

• Sharing of instruments/reagents/chemicals. How many times have you realized that you are out of a certain chemical and there is no way to get a new batch in time. Maybe that new person you chatted with at the lab nearby can spare enough to get you out of a pickle.

• New friends. The lab community is full of interesting, amazing people who you may have a connection with beyond the basic chit chat.  If nothing else, you now have familiar faces to say hello to at future conferences and trainings.

• Future job opportunities. Being able to put a face with a name increases the likelihood of standing out in a sea of resumes.

• Growing your skill set. Networking can open the door to new programs, projects, and professional organizations that can all help you grow in your professional career.

So, what to do if you like the sound of these outcomes, but don’t feel comfortable at networking events?  First of all, not many people truly feel comfortable networking, so keep it in mind that the person standing next to you may be just as uncomfortable as you.  If mingling is not your strong suit, try setting a goal of talking to just one or two people or getting an answer to a very specific lab issue at an event.  One easy way to get to know others at networking events is to ask lots of questions.  A few to get you started:

• What lab do you work in and what analyses do you do?

• Do you use any contract labs for anything? Do you like them?

• What analysis do you have the most issues with? Why?

• Are there any new methods you are considering keeping in-house?

• What certifications do you have/what auditors have you worked with? What has your experience been with them?

• What do you anticipate being the biggest challenge for your lab in the coming year?

• What are the biggest successes you have had?

Keep all this in mind when you come to the holiday social this December 6^th!  We all love to see new faces as well as catch up with those we haven’t seen in a while. 

 

The City and County of Broomfield has been contracting low-level mercury analyses for many years. The permit requires monthly sampling of the effluent.  We also collect upstream and influent samples for comparison. The sampling requires two people to grab four samples a day (every two hours) and then prepare a flow proportional composite from these samples.  The contract lab was awesome because they would provide us with a cooler with everything that we needed for the sampling event (pre-cleaned bottles, bags, gloves).  We would send them the individual bottles and then they would composite the samples based on the flow data that we provided.  However, on several occasions, the bottles broke during transit.  Also, it often took weeks to get the results to us.  Since this is a required monthly test, this was stressful, because we would need to know before the end of the month if there was an issue with the sample, so we could resample if necessary.

 

As we were planning for a laboratory expansion in 2015, we discussed the possibility of bringing this analysis in-house.  We visited the City of Ft. Collins wastewater lab and Ginger Wynne and the staff were kind enough to give us a tour of their lab and show us their low-level mercury setup.   We realized that we didn’t need a “clean” room, so we started thinking that this could work for us. We worked with the design team to create a metals/mercury lab with PVC fume hoods and polypropylene cabinets. The instrument’s autosampler can be covered to prevent contamination from environmental factors in the laboratory.

 

We purchased the mercury analyzer with the expansion and waited until we had everything else set-up in the lab before we brought in the instrument.  The laboratory was completed in August 2017 and the analyzer setup and training occurred the first week of October 2017.  After the initial training, it took a few more weeks to get the argon gas sparging system setup.  By April 2018, the method development was complete, and the first monthly samples were analyzed in-house.  Starting in August 2018, we will also begin analyzing our industrial pretreatment samples in-house.

 

So, if you were thinking that you have to have a Class 1 cleanroom to perform low level mercury analyses, maybe this will make you realize that isn’t necessary.  You do need to have a dedicated “clean” space that is not near any analyses that have mercury in a reagent (looking at you TKNs) and analysts that are diligent about keeping that space clean.

 

 

 

 

Lesa Julian is the Wastewater Laboratory Supervisor for the City and County of Broomfield.

On July 27, 2018 about 13 people braved the gorgeous weather and semi-busy Friday afternoon westbound traffic on I-70 to travel to Georgetown on a RMWEA sponsored tour of the Georgetown Wastewater Treatment Plant. Besides the learning opportunity and the chance to be in the mountains, beer after the tour at the local Guanella Pass Brewery was also offered as enticement. No wonder the tour was fully booked!

 

The tour focused on the improvements to nutrient and metal removal technologies that were completed in 2011. These treatment upgrades include an Integrated Fixed-film Activated Sludge system (IFAS) and tertiary polishing of the effluent before chlorination and discharge.

 

The 2009-2011 Georgetown WWTP upgrades increased the rated flow by 40%, up to 1.2 MGD. The current average flow is between 0.3 MGD and 0.6 MGD. There is still a lot of room to grow, but there is a large new construction project about a mile upstream from the WWTP that is expected to increase flows by 30% when it is complete.

 

Once entering the plant (by the way, all flows to the Georgetown WWTP are gravity fed-the city does not have a single pump station), the influent is screened and then enters the secondary treatment area (no primary clarification needed!).

 

 

The upgrades included addition of an additional secondary basin with IFAS included for both basins. The attached biomass on the IFAS media (which always looks like tiny plastic pizzelle cookies to me – sorry if you loved pizzelles!) provides increased nitrogen removal (nitrification/denitrification) and some phosphorus removal, while the traditional flocculated activated sludge provides traditional BOD and TSS removal. On the day we were there we were told that both basins were being used, but that the operators go down to one basin during the winter due to reduced flows. The IFAS media takes up about 40% of the volume of each basin, and while the SRT in the basins for the flocculated activated sludge is about 21 days, the media has yet to be replaced after seven years.

 

Effluent from the secondary enters an equalization (EQ) tank. This is the old secondary clarifier that has been modified to be used as an EQ tank. After the EQ tank, the effluent enters the new secondary clarifier, where it remains for “a few hours” before going to the sand filters.

The sand filters are the other main technology that was added during the 2009-2011 upgrade. It is an upflow system with two passes. The upflow system allows the effluent to enter at the bottom of the conical shaped filter area and then flow against the flow of the sand. This technology reduces both phosphorous and metals by 90-95% during each pass.

 

Georgetown is currently discharging phosphorous at well below their permit limit of 0.3 ppm which equates to greater than 90% removal from their influent phosphorus of 3-4 ppm. Metals such as copper, zinc, cadmium, and lead are also greatly reduced using the sand filters.

 

After polishing in the sand filters, the effluent enters a traditional chlorine contact basin where it has about 30 minutes contact with chlorine before being dechlorinated with sodium bisulfate before being discharged into Clear Creek right below Georgetown Lake. Georgetown WWTP now uses sodium hypochlorite for disinfection, but they used to make chlorine gas on site!

 

On the solids side, Georgetown uses a screw press to dewater their solids after digestion. Biosolids are then sent to McDonald farms in Denver, as they do not meet land application requirements. Georgetown is happy to have their own screw press (especially since it works great and can achieve 26% solids), as they used to have to share only a mobile screw press between them, Idaho Springs, and Morrison!

 

Thanks to the City of Georgetown and RMWEA for the great tour. I was unable to make the beer part of the tour, but I still had a great time and learned a lot!

 

Richard MacAlpine holds an MS in Environmental Science (WQ Emphasis) from CU-Denver, is on the Education Subcommittee of RMWQAA, and has worked in the lab at Metro Wastewater Reclamation District for the last decade plus.