Taking Barley Beyond Bread, Beer and Beef Stew

How LASAN Discovered Barley – LA’s Newest (And Most Unexpected) Water Quality SuperHero 

 

If you were to ask Angelenos what barley is used for, most would say for making bread, beer, or a hearty beef stew. 

 

Few would know that barley straw – a small, unassuming grass – has a secret super power that can improve water quality in lakes and ponds by controlling problematic algae blooms. In fact, the use of barley – specifically barley straw liquid extract – is a newfound discovery by LA Sanitation and Environment’s Watershed Protection Division staff in their ongoing quest to improve the water quality in LA’s lakes and constructed wetlands.

 

We recently sat down with Roulene Diego, Chemist II in LA Sanitation to discuss the Algae Bloom Natural Management at South Los Angeles Wetlands with Barley Straw Liquid Extract Pilot Study. Roulene has successfully worked on the study with a small team over the past few years.  Roulene told us about the pilot study, how her backyard became a working laboratory during the 2020 Covid shut down and possible future uses of barley straw liquid extract in LA’s water bodies.

 

LA Stormwater: Tell us about the problem that LA Sanitation was interested in solving?

 

Roulene: The South LA Wetlands has been experiencing algae blooms for a number of years, which has created a lot of concern. While algae occur naturally in water bodies, an algal bloom can disrupt a water body’s natural balance and degrade water quality. Algae can lead to human health issues and dead zones. It also looks bad and gives residents the impression of neglect. 

 

LA Stormwater: Did LASAN explore other possible solutions before trying barley straw liquid extract?

 

Roulene: Yes. In previous years, algae blooms in the South LA wetlands were managed using mechanical methods that included a fountain and recirculation system. Staff physically removed the algae from the water using skimmers and rakes. However, these methods did not result in the effective management of the algae, which was persistent year round.

 

LA Stormwater: What made LASAN look at barley straw liquid extract as a solution?

 

Roulene: Since traditional methods of algae removal at the wetlands had not produced positive results, WPD manager Alfredo Magallanes decided to look at alternatives. I found out that most algae management methods that exist involve high maintenance and can harm the environment. They take a long time to produce positive results and can be very expensive.

 

So, my manager and I shifted our research efforts to look for a method that was natural, effective, and safe for the environment. With the support of our Division Manager, Alfredo Magallanes, I suggested we do research on the use of barley straw liquid extract. We decided to explore it because it’s effective, easy to apply and safe for fish, wildlife, plants, and animals and is inexpensive. 

 

LA Stormwater: Barley straw seems like an unlikely solution. How does something as innocuous as barley straw liquid extract solve an overgrowth of algae?

 

Roulene: Once barley straw liquid extract is applied to water that then receives sunshine, a natural chemical reaction occurs releasing chemical compounds that stop the growth of new algae cells. That leads to clearer water. And while the small amount of natural chemicals produced creates an inhospitable environment for algae, it doesn’t harm fish, birds, and plants. 

 

LA Stormwater: What was the next step in deciding that barley straw liquid extract could be the solution?

 

Roulene: We decided to do a bench pilot study to determine the effectiveness of the barley. A small-scale pilot study was needed prior to a full-scale application in the South LA Wetlands.

 

The bench pilot study was developed and completed in my backyard in the midst of the 2020 Covid lockdown. I split the samples into separate containers and added different concentrations of the barley straw liquid extract into each container. One control container held no barley straw liquid extract. During my daily observation, I noted all the variables (e.g. sunlight intensity, weather temperature) that can impact the growth of algae and recorded water quality data (e.g. pH, temperature, oxygen levels) to determine any significant change during the process. I also performed visual inspections and took photographs as part of the study.

 

This bench pilot study showed that while the control container contained algae growth, the rest of the containers that had received an application of the barley straw liquid extract resulted in less or no algae growth at all. The fish collected from the wetlands also did well throughout the study. The water quality data values for the samples containing the barley straw liquid extract showed no significant change from start to finish of the study. In conclusion, the bench pilot study successfully demonstrated that the barley straw liquid extract could control algae growth. Now it was time to do a full-scale pilot study.

 

In Spring of 2022, I started to manage the full-scale application of the pilot study at the South LA Wetlands. Almost immediately positive results were observed with just a few applications of the barley straw liquid extract. Throughout 2022, I continually observed and evaluated the South LA Wetlands. As of early 2023, the water in the South LA Wetlands remains clear of algae. This was the first time in years that we have not observed algae blooms.

 

LA Stormwater: How much does the barley application cost and how does this compare to other methods?  

 

Roulene: Barley application costs will vary on the waterbody size and the extent of the algae blooms.  Initial applications may be extensive if the quality of the water is severely degraded, which will increase the amount of the initial investment.  For the South LA Wetlands, the purchase of the barley straw liquid extract is approximately $13,000 per year. Adding labor, the total cost is approximately $30,000 per year. However, the total annual cost is much less than the manual removal of algae through skimming, which could cost up to $120,000 per year. Barley straw liquid extract application is clearly the most cost effective method. 

 

LA Stormwater: How often does the barley need to be applied to the algae? And, what is the application process?

 

Roulene: Barley straw liquid extract begins working as soon as it is applied to the water with the right preparation of the waterbody. Generally, we apply barley straw liquid extract to the area where the water circulation is the greatest.

 

The application for South LA Wetlands started with skimming matured algae before spraying the extract in the water. This took place with a once-a-week schedule, moving to every two weeks, and immediately moved to once a month, and ultimately on an as needed basis for maintenance purposes about once every three to six months.   

 

During the initial application, an on-site training of staff on the correct handling and application of the extract was conducted. The wetland was then first inspected to help us assess the severity of the algae bloom so that we can apply the right amount of barley straw liquid extract. The mature algae were manually removed by skimming and then barley straw liquid extract was manually sprayed in the water. 

 

LA Stormwater: What were the initial results of the pilot study? Are there any future plans for applying this to other water bodies in LA?

 

Roulene: We were very pleased with the positive results of the 2022 South LA Wetlands pilot study. Though there were negligible amounts of algae present throughout the year 2022, the barley straw liquid extract applications were able to effectively manage the algae growth without water quality being negatively impacted. 

LASAN is now considering the use of this approach to manage algae growth at Echo Park Lake – a much larger waterbody. Depending on those results, the use of barley straw liquid extract on other City urban lakes will be evaluated. 

 

The management of algae varies with each water body but we’re encouraged that we’ve found a solution that will successfully address the algae growth issue that has plagued the South LA Wetlands for years. We’re excited to apply this discovery to other lakes and constructed wetlands in Los Angeles.

 

A huge thank you and acknowledgement to fellow LA Sanitation and Environment team members – Led by Alfredo Magallanes (LASAN’s Watershed Protection Program Manager) and Emeverto Cheng (LASAN Engineer) who both provided guidance and assistance throughout the study. A special thank you to Jon Ball, Carlos Aldalpe and Michael Baluyot of LASAN WPP’s Pollution Assessment Section, who collected South LA Wetlands water samples and provided test kits and equipment to use for the pilot study and to Octavio (Gus) Edeza of LASAN’s Clean Water North Conveyance Division who supervised the removal of algae and application of the barley straw liquid extract at South LA Wetlands.