Table 10-12.Variations in Performance and Some Common CausesContinued
Population and industrial
Bypassing leakage (ex-
Decreased water use.
Discharge of hot wastes.
Inefficient operation due
to septic conditions, poor
s e t t l i n g , a n d o t h er
Industrial discharges. Slug
loading or dumping.
Chlorine feed equipment
not properly working.
Consider installing holding ponds or tanks. Con-
sult with industry to prevent dumping
during high flow periods. If increased flow is
expected to be continually above treatment plant
design capacity, plant expansion and/or
modifications should be considered.
Check collection system for unauthorized storm
and surface water connections. Enforce sewer
use regulations. Repair or replace broken or
cracked pipes and leaky joints. Raise or provide
good surface drainage for manhole covers in low
areas. Install holding ponds or tanks.
Check collection system for leaks and bypass-
ing. Make necessary repairs. Notify appropriate
regulatory officials at once. Request their advice.
Recirculate enough of the treatment plant
effluent to primary clarifier, trickling filter (or
other unit) to prevent excessive detention time
and provide better operation.
Enforce sewer use regulations if temperature is
high enough to hinder operation.
Locate points of entrance. Repair if needed.
Enforce sewer use regulations, if applicable.
Check on efficiency of each treatment unit. Ad-
just controls to secure maximum efficiency.
Check sludge-pumping schedule and rate, recir-
culation of effluent, aeration rate, trickling filter
operation, and return of digester supernatant.
Check for proper detention time in clarifiers and
If possible, secure cooperation of industry in
controlling time and rate of discharging strong
Check accuracy of dosing equipment. The
problem could be improper dose instead of in-
creased chlorine demand. Find out if chlorine
and wastewater are being properly mixed.
Wastewater with high temperature usually re-
quires more chlorine to satisfy the chlorine