The influence of simulated rainfall on the survival of fecal coliforms and coliphage on bermudagrass (Cynodon dactylon L.) and rhodesgrass (Cholris gayana Kunth.) following applications of liquid digested sludge containing varying amounts of solids was investigated using the most probable number and plaque count techniques, respectively. The numbers of coliphage on the grass decreased rapidly with drying time and at 48 hours after application none were detected in any of the treatments. Rainfall was effective in decreasing the coliphage levels, both immediately after sludge application and after a period of drying. Fecal coliform counts were decreased only slightly during rainfall, and the timing of rainfall in relation to drying time appeared to have little influence on residual populations. The survival of fecal coliforms on grass which did not receive rainfall was dependent on the climatic conditions to which the grass was exposed and much less dependent on the initial population of bacteria or the species of grass. The present study indicates that fecal coliforms can survive on pasture grasses for periods of 2 to 3 weeks after sewage sludge application and that rainfall will have little influence on the length of survival.

In the past five years sewage‐treatment systems, based on artificial reed beds, have created much interest in Europe. In the UK, reed bed treatment systems have attracted this interest because of their potential for producing cost‐effective treatment for small communities. In 1985 a UK coordinating group was established to produce an integrated research and development programme for evaluating the process. This paper briefly describes the principles lying behind reed bed treatment systems, and outlines the progress which has been made to January 1988. The results of performance from eight full‐scale and pilot‐scale systems are presented in detail.