Document Type

Research Poster

Publication Date



Human beings are changing not just global temperature but even the makeup of the water in our planet's rivers and streams. The Tapia Water Treatment Facility is located in the upper section of Malibu creek and treats around 9.5 million gallons per day of water which is then released into the Malibu watershed. This water is treated using chemicals not typically found in local streams and these chemicals may be harming the organisms that live downstream of the water treatment plant. Downstream from the Tapia water treatment plant we were able to find increased levels of both nitrates and phosphates from 0 ppm above the facility to 2 ppm of both nitrates and phosphates below the facility. The purpose of this study was to determine if the treated water released from the Tapia water treatment facility decreases the fitness of Duckweed (Lemna minor). In the field, we collected untreated water from above the facility and treated water during a release period from the facility. We then massed portions of duckweed and placed them in containers filled with either treated or untreated water. The duckweed was then allowed to grow in these containers for ten days and then reweighed at the five and ten day marks. We then compared the percent growth between these two treatments and found that there was a significant difference between the growth of the treated and untreated groups. The untreated groups had an average percent growth of 123.78% over the ten days while the treated groups had only 72.18% growth. We were able to determine that treated water from the Tapia Water Treatment Facility does reduce the fitness of Duckweed and therefore likely reduces the fitness of other aquatic plants as well.