Statistics in Hydrology

Introduction: PM Solutions Research has been surveying organizations about their project management practices for more than 15 years. This Project Manager Skills Benchmark was designed to help you understand the current skill levels of project managers – what skills project managers have and how these skills impact project and organizational success. The goal is to help you understand where to focus your project manager improvement efforts and thereby improve your project results.

On a hot summer day, who wouldn't want to jump into a cool and refreshing pool? And then, as the sun sets, what better way to relax than to slip into your own backyard spa -- summer or winter? But enjoying all that requires some regular attention. Remember, the water in your pool and spa is an ever-changing environment that calls for constant and careful monitoring. For some, this means hiring a professional service technician to come by once or twice a week. You can, however, take care of your pool and spa yourself. The need to treat water has been widely accepted for a long time. Sanitation, especially, is recognized as a means of controlling communicable diseases. The pool operator is expected to provide safe, clean water for bathers. More recently, however, the importance of mineral saturation, or 'water balance" as it is more popularly known, is recognized by those responsible for maintaining the pool and equipment. Water can become aggressive and destroy pools with corrosion, or it can become scaling and damage the pool with mineral deposits. The pool operator must learn about the use of chemical agents for sanitation and for control of pH, total alkalinity and calcium hardness. The operator is expected to protect both the swimmers and the pool itself. This chapter is written to present the necessary chemical treatments and sufficient background information to know when and how to use them.