1
 
   SUPPLEMENT NO. 1 TO PROSPECTUS INCLUDED IN POST-EFFECTIVE AMENDMENT NO. 1
 TO REGISTRATION STATEMENT NO. 333-59199. SUPPLEMENT IS FILED PURSUANT TO RULE
                                   424(B)(3)
 
                            WASTE CONNECTIONS, INC.
 
 SUPPLEMENT NO. 1 TO PROSPECTUS DATED SEPTEMBER 9, 1998, RELATING TO 3,000,000
                             SHARES OF COMMON STOCK
                           OF WASTE CONNECTIONS, INC.
 
     Since the date of the Prospectus, Waste Connections, Inc. (the "Company")
has acquired the following solid waste services businesses:
 
     Youngclaus Enterprises. On September 9, 1998, the Company acquired certain
collection assets from Youngclaus Enterprises, which "tuck in" to its Madera
operations.
 
     Country Garbage Services, Inc. On September 21, 1998, Waste Connections of
Utah, Inc., a wholly owned subsidiary of the Company, acquired certain assets of
Country Garbage Services, Inc., which provides solid waste collection and
transportation services in central Utah.
 
     Affiliated Waste Services, L.L.C. On September 18, 1998, Waste Connections
of Nebraska, Inc., a wholly owned subsidiary of the Company, acquired
substantially all the assets of Affiliated Waste Services, L.L.C., which
provides solid waste collection and transportation services to approximately
4,700 customers in Norfolk, Nebraska.
 
     Wolff's Trashmasher and Haul It All Sanitary Service. On September 18,
1998, Waste Connections of Nebraska, Inc. acquired substantially all of the
assets of Wolff's Trashmasher and Haul It All Sanitary Service, two sole
proprietorships that provide solid waste collection and transportation services
to approximately 1,400 customers in Stanton and Norfolk, Nebraska, and certain
unincorporated areas of Stanton, Nebraska.
 
     Evergreen Waste Systems, Inc. On September 21, 1998, a wholly owned
subsidiary of the Company merged into Evergreen Waste Systems, Inc. As a result
of this merger, Evergreen Waste Systems, Inc. became a wholly owned subsidiary
of the Company that provides solid waste and recyclables collection and
transportation services to more than 6,650 customers in Washougal, Camas and
Vancouver, Washington, and unincorporated areas of Clark County, Washington and
Multnomah County, Oregon.
 
     Harrell's Septic Service. On September 22, 1998, Curry Transfer and
Recycling, a wholly owned subsidiary of the Company, acquired certain business
assets of Harrell's Septic, which provides portable toilet and septic services
in Crescent City, California, Del Norte and Humboldt Counties, California, and
Curry, Oregon.
 
     Westlane Disposal. On September 25, 1998, Curry Transfer and Recycling
acquired certain business assets of Westlane Disposal, which provides solid
waste collection and transportation services to approximately 2,210 customers in
Lane, Lincoln and Douglas Counties, Oregon.
 
     In addition, on September 16, 1998, the Company received a preliminary
letter of commitment to amend and increase its credit facility with a syndicate
of banks led by BankBoston, N.A. The amendment will, among other things,
increase the Company's borrowing capacity from $60.0 million to $120.0 million
and modify certain covenants, and it may lower the Company's borrowing costs.