Licensed Septic Companies in Merrimack, NH
13 septic companies serve Merrimack, New Hampshire, and 13 of them hold a New Hampshire septic license or certification matched to the New Hampshire Department of Environmental Services, Subsurface Systems Bureau list (data as of October 2026).
Septic services in Merrimack
Guides: Septic system installation · Installation cost · Pumping cost
13 septic companies in Merrimack
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Dupont Landscape & Excavation
101 Turkey Hill Rd, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #05395 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
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Eric Twardosky
Po Box 250, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #04068 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
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Jerome P Hill
5 Oxford St, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Designer and Installer · #02963 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
- Licensed: New Hampshire NHDES Permitted Septic System Designer and Installer · #04417 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation · Perc testing
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Robert C Lavoie
11 Brieann Dr, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #04819 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
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Tom Howe Septic Systems
29 Patten Rd, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #03783 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
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David Dupont
101 Turkey Hill Rd, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #05396 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
No phone on the state list
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Dennis Lambert
102 Amherst Rd, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #05125 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
No phone on the state list
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Kenneth S Howe
81 Baboosic Lake Rd, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #03782 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
No phone on the state list
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Michael Bachand
17 Westborn Dr, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #04975 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
No phone on the state list
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Robert Mccabe
30 A Wilson Hill Rd, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #01600 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
No phone on the state list
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Ronald Bosquet
80 Amherst Rd, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #04867 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
No phone on the state list
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Thomas Howe
29 Patten Rd, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #00840 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
No phone on the state list
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Wade Parks
41 Peaslee Rd, Merrimack, NH 03054 · Hillsborough County
- Licensed: New Hampshire NHDES Permitted Septic System Installer · #03275 (New Hampshire Department of Environmental Services, Subsurface Systems Bureau, verify)
Per state license: Installation
No phone on the state list
No listings match those filters.
Septic licensing in New Hampshire
New Hampshire requires a NHDES permit to design or install a septic system; the Subsurface Systems Bureau publishes the list of permitted designers and installers. The NH Department of Environmental Services, Subsurface Systems Bureau issues these credentials: Permitted installer (RSA 485-A:36); Permitted designer.
Permits for new systems, replacements and most repairs are issued locally. Ask the contractor which office handles Merrimack and whether the permit fee is in their quote.
New Hampshire septic licensing: agencies, license types and how to check a license →
Septic companies in Merrimack: common questions
How many licensed septic companies are in Merrimack, NH?
13 septic companies serve Merrimack, New Hampshire, and 13 of them hold a New Hampshire septic license or certification matched to the New Hampshire Department of Environmental Services, Subsurface Systems Bureau list (data as of October 2026). Each license badge on this page names the agency and links to its lookup so you can confirm it.
Who licenses septic contractors in New Hampshire?
New Hampshire requires a NHDES permit to design or install a septic system; the Subsurface Systems Bureau publishes the list of permitted designers and installers. The licensing body is the NH Department of Environmental Services, Subsurface Systems Bureau.
Which companies install septic systems in Merrimack?
13 listings in Merrimack install septic systems. New systems and replacements need a permit, so ask each installer to handle the permit and to show their New Hampshire license.
How do I check a septic contractor's license in New Hampshire?
Use the NH Department of Environmental Services, Subsurface Systems Bureau's lookup (https://www.des.nh.gov/land/septic-systems/septic-designer-or-installer) and search the contractor's name or license number. Our guide to checking a septic license walks through it.