"I am going to write a letter to Prime Minister Narendra Modi soon in this regard," Pathak told reporters.
Pathak is the founder of Sulabh International, a social service organisation which works to promote human rights, environmental sanitation, non-conventional sources of energy, waste management and social reforms.
Pathak gave a cheque of Rs 1.5 lakh to a woman for construction of toilet at her home in Sadisopur village of Patna district.
Pathak said more than a crore households particularly in rural areas were bereft of toilet due to which people have to practice open defecation.