Using Chlorophyll-a as a Surrogate for pH in Lake Eutrophication TMDLs: A Simplified Approach

Author: Ikenberry Charles D.  

Publisher: Water Environment Federation

ISSN: 1938-6478

Source: Proceedings of the Water Environment Federation, Vol.2009, Iss.6, 2009-01, pp. : 1059-1072

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Increased productivity and growth of algae is the leading cause of impaired lakes on Iowa's Draft 2008 303(d) list. Elevated pH levels often accompany increased algal growth, and pH contributes to impairments in a significant number of Iowa lakes. TMDL developers often lack a sufficient suite of available climate, hydrologic, and water quality data required for development of complex water quality models. Simplified approaches to TMDL development are often preferred over complex and highly detailed methods due to limited data, time, resources, and modeling expertise. However, many simple lake models do not simulate pH. This paper and presentation discuss the development of a lake pH TMDL using simple and commonly used modeling tools and chlorophyll-a as a surrogate for pH. Lake Geode, a 174-acre man-made reservoir in southeast Iowa, serves as the case study.