CBSE Class 7 Answered

Open drainage systems for sewage deposits are hazardous in the following ways:

• Foul smell which affects our health.
• Harmful microorganisms enter and disrupt our body system.
• When insects like housefly sit on the garbage which is being drained, these flies carry the pathogens and sit on food material and enter our body to cause diseases.
• Groundwater contamination
• Decrease in soil productivity
• Contamination of vegetables and crops grown in wastewater
• Foul-smelling open drains originate from individual houses and join the big drain and fall ultimately into the rivers.