Water and Waste Management

WATER & WASTE MANAGEMENT, part of MultiEducator's "Formulator" line, is the
  essential tool for any Water & Waste Management engineer or engineering
  student. This comprehensive application contains over 245 specialized
  engineering formulas covering all major areas of water and wastewater
  engineering, plus nearly 900 conversion formulas — over 1,100 formulas in
  total.

  Engineering categories include: Water Flow, Groundwater, Sewage Treatment,
  Pollution, Activated Sludge & Sludge Digestion, Water Supply, Facilities
  (Chemical Dosing, Distribution, Disinfection & Laboratory), Storm Runoff,
  Sewer Pipe, Waste (Gases, Liquid & Solid), River Pollution, Hydraulics
  (Hazen-Williams, Darcy-Weisbach, Bernoulli), Pumping (Horsepower, NPSH,
  Affinity Laws), Water Treatment (Chlorine Dosage, CT Values, Chemical Feed
  Rates, Filtration), and Wastewater Operations (BOD Loading, SVI, F/M Ratio,
  MCRT, Detention Time, Removal Efficiency).

  The app also includes conversion calculators for Area & Volume, Pressures,
  Linear Measure, Weights, Liquid Measures, Cubic Measures, BTU, Horsepower,
  Watts, Power, Hydraulic, HVAC, Flows, and over 460 Metric conversions — plus
  eight temperature scale converters.

  All formulas display results in both US and Metric units with a single toggle.
   Calculations can be saved, exported, and shared. Toggle between US and Metric
   units instantly. If you need a formula we haven't included, just email us and
   we'll add it in the next update.