Wastewater reuse involves using treated wastewater or sewage for purposes other than its initial use, such as for irrigation, industrial processes, or replenishing groundwater. The most common reasons for establishing wastewater reuse programs are to identify new water sources due to increasing demand and to meet more stringent wastewater discharge standards. While reuse provides benefits, careful treatment is needed to address public health risks from pathogens and emerging pollutants, as well as environmental risks such as eutrophication from excess nutrients in reused water.

1. What is wastewater reuse?
• The U.S. Environmental Protection Agency (EPA)
defines wastewater reuse as, “using wastewater or
reclaimed water from one application for another
application. A common type of recycled water is
water that has been reclaimed from municipal
wastewater (sewage).”

2. Reasons for wastewater reuse
The most common reasons for establishing a
wastewater reuse program is to identify new water
sources for increased water demand and to find
economical ways to meet increasingly more stringent
discharge standards.

3. Types of Reuse
• Urban reuse-the irrigation of public parks, school yards ,
highway medians, and residential landscapes, as well as for
fire protection and toilet flushing in commercial and
industrial buildings.
• Agricultural reuse-irrigation of non food crops, such as
fodder and fiber, commercial nurseries, and pasture lands.
High-quality reclaimed water is used to irrigate food crops.
• Recreational impoundments-such as pond sand lakes.
• Environmental reuse-creating artificial wetlands, enhancing
natural wetlands, and sustaining stream flows.
• Industrial reuse-process or makeup water and cooling tower
water.

4. Technical Description
• One of the most critical steps in any reuse program is to
protect the public health, especially that of workers and
consumers.
• To this end, it is most important to neutralize or eliminate
any infectious agents or pathogenic organisms that may be
present in the wastewater.
• For some reuse applications, such as irrigation of nonfood
crop plants, secondary treatment may be acceptable. For
other applications, further disinfection, by such methods as
chlorination or ozonation, may be necessary.

5. Application of treated wastewater
• Agricultural Irrigation
Crop irrigation
Commercial nurseries
• Landscape Irrigation
Parks
School yards
Highway medians
Golf courses
Cemeteries
Residential

6. Application of treated wastewater
• Industrial Recycling and Reuse
Cooling water
Boiler feed
Process water
Heavy construction
• Groundwater Recharge
Groundwater replenishment
Saltwater intrusion control
Subsidence control

7. • Recreational / Environmental Uses
Lakes & ponds
Marsh enhancement
Stream-flow augmentation
Fisheries
• Non-Potable Urban Uses
Fire protection
Air conditioning
Toilet flushing

8. Problems associated with
wastewater Reuse
• Heavy Elements
• Public Health – nervous system disorders, mutagenesis,
teratogenesis, carcinogenesis
• Bioaccumulation (food chain on crops and animals)
• Surface water pollution
• Environmental Impact – acute and chronic toxicity for plant
and animal life,
• chronic degradation effect on soil

9. Problems associated with
wastewater Reuse
• Nutrients (N & P)
• Public Health – blue-baby syndrome (from NO3-)
• infiltration into potable water supplies
• Environmental Health – Eutrophication, crop yield effects
(+ive & -ive)
• Surface water pollution
• Irrigation practices

10. Problems associated with
wastewater Reuse
• Dissolved Solids (salinity)
• Environmental Health
Induce problems for the crops’ yield selection and
quantity
Accumulation in soil
Effect on soil permeability
Clogging drip-irrigation systems
• Emerging Pollutants
• Public Health
Acute and chronic health effects – effect on growth,
reproduction problems