<Page>
Exhibit 3.84
STATE OF NEW YORK }
SS:
DEPARTMENT OF STATE }
I HEREBY CERTIFY THAT THE ANNEXED COPY HAS BEEN COMPARED WITH THE ORIGINAL
DOCUMENT IN THE CUSTODY OF THE SECRETARY OF STATE AND THAT THE SAME IS A TRUE
COPY OF SAID ORIGINAL.
WITNESS MY HAND AND SEAL OF THE DEPARTMENT OF STATE ON MAY 28, 2002
[SEAL]
/s/ [ILLEGIBLE]
SPECIAL DEPUTY SECRETARY OF STATE
DOS-1266 (7/00)
<Page>
F960715000069
CERTIFICATE OF INCORPORATION
OF
SPRINGER WASTE MANAGEMENT, INC.
Under Section 402 of the Business Corporation Law
IT IS HEREBY CERTIFIED THAT:
The name of the corporation is: Springer Waste Management, Inc.
The purposes for which this corporation is formed are as follows:
To engage is any lawful act or activity for which corporations may be
organized and operate under the Business Corporation Law of New York. It is not
formed to engage in any act or activities requiring consent or approval of
another state agency, board or department.
The aggregate number of shares which the corporation shall be authorized to
issue is 200 shares non par value.
The office of the corporation is to be located in the County of Saratoga, State
of New York.
The designated agent of the corporation upon whom the process against may be
served is Ronald H. Sinzheimer, Esq., P.C. The post office address to which the
Secretary of State shall mail a copy of any process against the corporation
served upon him is:
Ronald H. Sinzheimer, Esq.
Office and P.O. Address
23 Elk Street
Albany, New York 12207
The undersigned incorporator is over the age of eighteen years.
IN WITNESS WHEREOF, this certificate has been subscribed on July 9, 1996,
by the undersigned who affirms that statements made herein are true under the
penalties of perjury.
Springer Waste Management, Inc.
By: /s/ Ronald H. Sinzheimer
-------------------------------
Ronald H. Sinzheimer Esq.
RONALD H. SINZHEIMER ESQ.P.C.
23 ELK STREET
ALBANY, NY 12207
1
<Page>
F960715000069
CERTIFICATE OF INCORPORATION
OF
SPRINGER WASTE MANAGEMENT, INC.
Under Section 402 of the Business Corporation Law
================================================================================
CERTIFICATE OF INCORPORATION
================================================================================
[STAMP]
STATE OF NEW YORK
DEPARTMENT OF STATE
[ILLEGIBLE]
Filed by:
RONALD H. SINZHEIMER, ESQ. P.C.
Office and P.O. Address
23 Elk Street
Albany, NY 12207
(518) 434-4439
<Page>
STATE OF NEW YORK }
SS:
DEPARTMENT OF STATE }
I HEREBY CERTIFY THAT THE ANNEXED COPY HAS BEEN COMPARED WITH THE ORIGINAL
DOCUMENT IN THE CUSTODY OF THE SECRETARY OF STATE AND THAT THE SAME IS A TRUE
COPY OF SAID ORIGINAL.
WITNESS MY HAND AND SEAL OF THE DEPARTMENT OF STATE ON MAY 28, 2002
[SEAL]
/s/ [ILLEGIBLE]
SPECIAL DEPUTY SECRETARY OF STATE
DOS-1266 (7/00)
<Page>
M 385 - Certificate of Amendment of Certificate of Incorporation
Business Corporation Law Section 805:12-85
COPYRIGHT 1972
BY JULIUS BLUMBERG, INC,
LAW BLANK PUBLISHERS
F960731000104
CERTIFICATE OF AMENDMENT OF THE CERTIFICATE OF INCORPORATION OF
SPRINGER WASTE MANAGEMENT, INC.
UNDER SECTION 805 OF THE BUSINESS CORPORATION LAW
IT IS HEREBY CERTIFIED THAT:
(1) THE NAME OF THE CORPORATION IS SPRINGER WASTE MANAGEMENT, INC.
(2) THE CERTIFICATE OF INCORPORATION WAS FILED BY THE DEPARTMENT OF STATE
ON THE 15TH DAY OF JULY 1996.
(3) THE CERTIFICATE OF INCORPORATION OF THIS CORPORATION IS HEREBY AMENDED
TO EFFECT THE FOLLOWING CHANGE*
The name of the corporation shall be changed to NEW ENGLAND WASTE SERVICES
OF N.Y., INC. Paragraph 1 of the certificate of incorporation is amended to
read as follows: 1. The name of the corporation is New England Waste
Services of N.Y., Inc.
*Set forth the subject matter of each provision of the certificate of
incorporation which is to be amended or eliminated and the full text of the
provision(s), if any, which are to be substituted or added. If an amendment
provides for a change of issued shares, the number and kind of shares changed,
the number and kind of shares resulting from such change and the terms of
change. If an amendment makes two or more such changes, a like statement shall
be included in respect to each change.
1
<Page>
There are no officers, directors or shareholders.
(4) THE AMENDMENT TO THE CERTIFICATE OF INCORPORATION WAS AUTHORIZED:
* STRIKE OUT WHERE INAPPLICABLE
2
<Page>
F960731000104
IN WITNESS WHEREOF, THIS CERTIFICATE HAS BEEN SUBSCRIBED THIS 30 DAY OF
JULY 1996 BY THE UNDERSIGNED WHO AFFIRM(S) THAT THE STATEMENTS MADE HEREIN ARE
TRUE UNDER THE PENALTIES OF PERJURY.
TYPE NAME CAPACITY IN WHICH SIGNED SIGNATURE
--------- ------------------------ ---------
Ronald H. Sinzheimer Attorney / Incorporator /s/ Ronald H. Sinzheimer
================================================================================
[STAMP]
CERTIFICATE OF AMENDMENT OF THE CERTIFICATE OF INCORPORATION OF
SPRINGER WASTE MANAGEMENT, INC.
UNDER SECTION 805 OF THE BUSINESS CORPORATION LAW
================================================================================
FILED BY: Ronald H. Sinzheimer, Esq., P.C.
ADDRESS: 23 Elk Street
Albany, New York 12207
(518) 434-4439
[STAMP]
STATE OF NEW YORK
DEPARTMENT OF STATE
FILED JUL 31 1996
TAX $
----------------
BY: /s/ [ILLEGIBLE]
----------------
SARATOGA
960731000105
3
<Page>
STATE OF NEW YORK }
SS:
DEPARTMENT OF STATE }
I HEREBY CERTIFY THAT THE ANNEXED COPY HAS BEEN COMPARED WITH THE ORIGINAL
DOCUMENT IN THE CUSTODY OF THE SECRETARY OF STATE AND THAT THE SAME IS A TRUE
COPY OF SAID ORIGINAL.
WITNESS MY HAND AND SEAL OF THE DEPARTMENT OF STATE ON MAY 28, 2002
[SEAL]
/s/ [ILLEGIBLE]
SPECIAL DEPUTY SECRETARY OF STATE
DOS-1266 (7/00)
<Page>
F010221000469
CT-07
CERTIFICATE OF CHANGE
OF
New England Waste Services of N.Y., Inc.
UNDER SECTION 805-A OF THE BUSINESS CORPORATION LAW
1. The name of the corporation is New England Waste Services of N.Y., Inc.
It was incorporated under the name Springer Waste Management, Inc.
2. The Certificate of Incorporation of said corporation was filed by the
Department of State on the July 15, 1996.
3. The following was authorized by the Board of Directors:
To change the post office address to which the Secretary of State shall
mail a copy of process in any action or proceeding against the corporation which
may be served on him from Tom West c/o Leboeuf, Lamb, Greene & Macrae LLP, 99
Washington Ave., Suite 2020, Albany, NY 12210 to c/o C T Corporation System, 111
Eighth Avenue, New York, N.Y. 10011.
To designate C T CORPORATION SYSTEM, 111 Eighth Avenue, New York, N.Y.
10011 as its registered agent in New York upon whom all process against the
corporation may be served.
/s/ Jerry S. Cifor
------------------------------------------
Jerry S. Cifor, Vice President & Treasurer
NY006-6/14/00 CT SYSTEM ONLINE
1
<Page>
F010221000469
CT-07
CERTIFICATE OF CHANGE
OF
NEW ENGLAND WASTE SERVICES OF N.Y. INC.
UNDER SECTION 805-A OF THE BUSINESS CORPORATION LAW
[ILLEGIBLE]
STATE OF NEW YORK
DEPARTMENT OF STATE
FILED FEB 21 2001
TAX $______________
BY: /s/ [ILLEGIBLE]
----------------
SARA
CASELLA WASTE SYSTEMS, INC.
25 GREENS HILL LANE
P.O. BOX 866
RUTLAND, VT 05701
010221000498
2