New Delhi, Oct 13 Prime Minister Narendra Modi will visit Bihar on Saturday where he will lay the foundation stones for four sewerage projects under the Namami Gange Programme and four national highway projects in Mokama area of Patna district. The total outlay of these projects will be over Rs 3,700 crore. The four sewerage projects for which the foundation stone will be laid are Sewage Treatment Plant at Beur, Sewerage System with Sewer Network at Beur, Sewage Treatment Plant at Karmalichak, and Sewage Treatment Plant and Sewer Network at Saidpur -- all in state capital Patna. "These projects together will create new STP capacity of 120 MLD and upgrade the existing 20 MLD for Beur," said an official statement. The four national highway projects for which foundation stones will be laid include four-laning of Aunta-Simariya section of NH-31 and construction of six-lane Ganga Setu. The other three projects are four-laning of Bakhtiyarpur-Mokama section of NH-31, two-lane construction of Maheshkhunt-Saharsa-Purnea section of NH-107 and two-lane construction of Biharsharif-Barbigha-Mokama section of NH-82. Modi will also address the Centenary Celebrations of Patna University.