Guest Column | January 9, 2015

Math Solutions: Most Popular 2014 Calculations

By Daniel Theobald, "Wastewater Dan"

Water Online takes a look back at 2014’s most sought-after “Math Solutions,” presented by wastewater consultant and trainer Dan Theobald (“Wastewater Dan”).

Math calculations on your certification exams or for operating your plant may require various calculation types: volume, poundage, flow, pump efficiency, and more.

Depending on your needs as a facility designer, regulator, educator, or operator, calculations and unit of expression require explicit formulas.

Based on reader response to “Math Solutions” published in 2014, the following calculations top the list of demands:

Calculate total dynamic head (TDH) of a pumping system using pressure-ft.:

Calculate BOD mg/L per day using flow and pounds:

Calculate gallons of a circular tank:

Calculate waste activated sludge (WAS) in GPM:

Calculate multiple flow-rate conversions:

Calculate pounds using array formula from multiple sources:

Complete playlist of Wastewater Dan’s Math Solutions

If you have specific wastewater math queries for Dan, 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.