Tahoe Stormwater Treatment

Chemical Treatment Methods Pilot (CTMP) for Treatment of Urban Runoff.  Phase I.  Feasibility and Design, 2002 - 2007

Collaborating Organizations:

Bachand & Associates, UC Davis Tahoe Research Group,  UC Davis Department of Civil and Environmental Engineering, and UC Davis Aquatic Toxicology Lab.

Funding Organization:

City of South Lake Tahoe, USDA Forest Service and Caltrans

Project Description:

Stormwater at dosing

6 hours after dosing


Urban runoff within the Tahoe Basin is a major source of nutrients and small particles to Lake Tahoe, greatly contributing to reduced lake clarity (Jassby et al 1999; Reuter and Miller 2000; Jassby et al. 2001).  This project used laboratory and mesocosm studies to test the effectiveness of coagulants to remove phosphorus and fine particles from Tahoe area storm water under natural variations of temperature, water quality and other environmental conditions expected in the Tahoe Basin. The project also investigated potential toxicity of stormwater and the effects on that toxicity when treating stormwater with coagulants.  Toxicity tests assessed effects on algae, zooplankton, and fish. 


Dr. Philip Bachand led the initiation of this study based upon research he had conducted as a Duke University researcher working in the Florida Everglades area.  As lead P.I., Bachand & Associates led the experimental design for coagulant testing and toxicity studies, and served as the main contact to the funding agencies, the City of South Lake Tahoe, the Forest Service and Caltrans, providing updates and technical presentation.  We worked with UC Davis scientist and engineers in selecting, testing and analyzing data for a variety of coagulants. In addition, Bachand & Associates designed toxicity experiments with the U.C. Davis Aquatic Toxicology Lab (ATL) and coordinated water sample collection, processing and delivery to the ATL.  Bachand & Associates were the lead authors on the two final reports, and has been lead author on several of the subsequent publications.  Three manuscripts from the project are planned and in various stages of publication. 

Publications and Final Reports

Bachand, P.A.M, A.C. Heyvaert, S.E. Prentice and T. Delaney .  2010. Feasibility study and conceptual design for using coagulants to treat runoff in the Tahoe Basin.  ASCE Journal of Environmental Engineering. J. Envir. Engrg. 136:1218-1231 doi:10.1061/(ASCE)EE.1943-7870.0000261. http://cedb.asce.org/cgi/WWWdisplay.cgi?271466

Bachand, P.A.M., S.M. Bachand, S. Lopus, A. Heyvaert and I. Werner.  2009. Treatment with Chemical Coagulants at Different Dosing Levels Changes Ecotoxicity of Stormwater from the Tahoe Basin, California, USA". Journal of Environmental Science and Health, Part A: Toxic/Hazardous Substances and Environmental 45(2), 137–154. http://tandfprod.literatumonline.com/doi/abs/10.1080/10934520903425459

Lopus, S. E., P. A. M. Bachand, A. Heyvaert, I. Werner, S. J. Teh, and J. Reuter. 2009. Potential toxicity concerns from chemical coagulation treatment of stormwater in the Tahoe Basin, California, USA. Accepted Journal of Ecotoxicology and Environmental Safety.  http://www.ncbi.nlm.nih.gov/pubmed/19428107

Bachand, P., A. Heyvaert, J. Reuter, I. Werner, S. Bachand, and S.J. Teh.  2007.  Chemical Treatment Methods Pilot (CTMP) System for Treatment of Urban Runoff – Phase I.  Feasibility and Design.  Final Report for the City of South Lake Tahoe. Submitted to the USFS and the City of South Lake Tahoe. February 22, 2007.   (Publicly available from Aquatic Commons).

Trejo-Gaytan, J, P. Bachand, J. Darby. 2006.  Treatment of Urban Runoff at Lake Tahoe: Low-Intensity Chemical Dosing. Water Environment Research 78(13): 2487-2500 http://www.ncbi.nlm.nih.gov/pubmed/17243249

Bachand, P., J. Trejo-Gaytan, J. Darby and J. Reuter.  2006.  Final Report:  Small-Scale Studies on Low Intensity Chemical Dosing (LICD) for Treatment of Highway Runoff.  Submitted to CALTRANS (California Department of Transportation) by University of California Davis.  April 19, 2006.    http://www.dot.ca.gov/hq/env/stormwater/special/newsetup/_pdfs/CTSW-RT-06-073-13-1.pdf

Bachand, P.A.M. and Bachand, S. and Heyvaert, A. (2005) BMP treatment technologies, monitoring needs, and knowledge gaps: status of the knowledge and relevance within the Tahoe Basin. ,Sacramento, CA. California State University Sacramento, Office of Water Programs ,(Technical Memorandum ,2007.01 ). http:(Publicly available from Aquatic Commons)