Guest Column | June 29, 2015

Math Solutions: More Flow Rate Conversion Calculations

By Daniel Theobald, "Wastewater Dan"

This edition of Water Online's “Math Solutions” series, presented by wastewater consultant and trainer Dan Theobald (“Wastewater Dan”), instructs operators on even more flow rate conversion calculations (see previous calculations).

This tool for operators — represented through video tutorials — offers mathematical templates for performing accurate wastewater calculations. The tool also provides definitions, explanations, and alternative applications for the calculations beyond the specific examples presented. In addition to operators, it may also serve educators, engineers, regulators, and others.

Practical applications for the tool include this presentation of wastewater conversion calculations, which are useful “on the job” as well as for wastewater certification examinations.

Conversion data is provided in many units of expression (e.g., horsepower, grams) and also many different time increments (e.g., seconds, minutes, hours, or days). Depending on the calculation used with conversions, converting the unit or time of expression may be required for an accurate calculation.

Some relevant conversion calculations are accessible below:

Convert horsepower (HP) to kilowatt hour (kWh):

Convert pounds (lbs.) to grams (gm):

Convert gallons to cubic yards:

Convert 24-hour infiltration rate of a pond in gallons into inches:

Complete playlist of Wastewater Dan’s Math Solutions   

This is the 'More Flow Rate Conversion Calculations' presentation in my series of “Math Solutions.” If you have specific wastewater math queries, please submit a question.

About Dan Theobald:

Known in the industry as “Wastewater Dan,” Daniel L. Theobald, proprietor of Environmental Services (, is a professional wastewater and safety consultant/trainer. He has more than 24 years of hands-on industry experience operating many variants of wastewater treatment processing units and is eager to share with others his knowledge about water conservation.

Theobald serves as an active consultant for industries looking to achieve and maintain improved wastewater treatment at reduced cost. He is a Lifetime Member of the Who’s Who Registry of Professionals and holds numerous certifications from wastewater management regulatory boards and professional organizations. Theobald contributed one chapter to the Water Environment Federation’s ( Manual of Practice # 37 (MOP-37), a technical manual resource guide for biological nutrient removal, published in 2013.