Research by DoINeedAPermit Research Team · Updated May 2026
The Short Answer
A like-for-like replacement pump in an existing sump pit is exempt. New pit excavation, ejector pumps for below-grade bathrooms, and discharge tied to municipal storm sewer all require a permit from Farmington Hills Building Department.
Farmington Hills enforces Michigan's Residential Code with a critical local amendment: the city's stormwater ordinance (Chapter 30 of the City Code) requires pre-approval for any discharge that connects to municipal storm sewers or crosses property lines, even if the pump itself might be exempt under state code. This is stricter than many neighboring Michigan communities — Troy and Bloomfield Township allow some discharge scenarios under administrative review without a full plumbing permit. In Farmington Hills, if your new sump pit will drain to a storm sewer, to a driveway swale that reaches a city right-of-way, or through a subsurface tile system, you must file a permit before the pit is dug. The city's 42-inch frost depth and glacial-till soils create persistent hydrostatic pressure — basement water damage is routine here — which explains why discharge location is non-negotiable. Replacement of an existing pump in an existing pit (same capacity, same location) is exempt unless you're upgrading to an ejector pump for a new below-grade bathroom, which requires venting and inspection under IRC P3108. Battery backup adds are typically exempt but are worth mentioning on your application if submitting one anyway.

What happens if you skip the permit (and you needed one)

Farmington Hills sump pump permits — the key details

Farmington Hills sits atop glacial till and sandy deposits that funnel water to basements year-round. The city's 42-inch frost depth (deeper than downstate) means sump discharge must be protected from freezing — any exterior discharge line must be buried below frost depth or run through an insulated conduit that extends 5 feet minimum from the foundation. The Building Department enforces both Michigan Residential Code R405 (foundation drainage) and the city's stormwater Chapter 30, which prohibits discharge to a neighbor's property, a municipal sanitary sewer, or a street right-of-way without written approval from the Engineering Division. This is the key local gate: many homeowners assume sump water can go anywhere because the pit itself isn't technically a sewage system. Wrong. In Farmington Hills, discharge is regulated as stormwater, and the pit location, pump capacity, and discharge path must all be shown on your permit application. New pits require a rough plumbing inspection before the pit is buried and a final inspection after the pump is running.

Ejector pumps — used for below-grade bathrooms or laundry rooms — are a different animal and always require a permit in Farmington Hills. An ejector pump must be installed in a sealed pit (not a sump pit) and must be vented through the roof per IRC P3108.1. The vent cannot tie into the drain-waste-vent system; it must run separately to air. Many contractors miss this or try to vent the pump into a basement window well — both rejected by Farmington Hills inspectors. The pump itself must be rated for the load (calculate gallons per minute from the fixtures), and a backup (battery or water-powered) must be shown on the installation detail. The city's Building Department sees two or three failed ejector pump installations per month — usually because the vent wasn't sized correctly or the backup system was omitted from the plan. If you're adding a basement bathroom, budget $300–$600 for the sump or ejector pump permit and $200–$400 for inspection time.

Replacement of an existing pump in an existing pit is exempt if the new pump is the same type and capacity as the old one and you're not changing the discharge location. If you pull out a 1/2 hp pump and install a new 1/2 hp pump in the same pit, no permit. If you're upgrading to a larger pump because the old one can't keep up with your water load, or if you're adding a second pit or moving the discharge, you'll need a permit. Backup pumps — battery-powered or water-powered — are exempt additions to an existing pit, but many homeowners include them in the permit application anyway for documentation purposes. The city doesn't require a backup pump for residential sump systems (unlike some commercial code), but it's the difference between a $500 repair and a $15,000 water damage claim when the primary pump fails during a heavy rain. Farmington Hills receives an average of 35 inches of rain annually, and spring melt often saturates clay soils for weeks at a time, so backup capability is practical insurance.

The permit application requires a site plan showing the pit location, the discharge path (including where the water exits the property or enters a city storm sewer), the pump model and capacity, and the vent location (if an ejector pump). If discharge goes to a city storm sewer, you'll need to identify the nearest catch basin and confirm the lateral distance from the foundation. The Building Department coordinates with the Engineering Division on discharge approvals; this can add 3-5 business days to the review. The permit fee is typically $125–$250, based on the job valuation (the city uses a formula of 1.5-2% of estimated cost, minimum $100). Rough inspection happens before the pit is buried; final inspection after pump installation and discharge testing. Both inspections must verify proper venting, adequate pit size (minimum 18 inches diameter for standard sump, larger for ejector), sump cover secured, and discharge line protected from freezing and damage.

Owner-builders are permitted to pull a sump pump permit for their own occupied home in Farmington Hills, but the application requires homeowner certification and a signed acknowledgment that you're liable for code compliance. Many owner-builders use licensed plumbers anyway because the venting detail and discharge approval can be tricky. If you hire a contractor, the contractor pulls the permit and is responsible for inspections. The city's online permit portal (accessible through the Farmington Hills city website) allows you to check application status, schedule inspections, and view inspection reports. Most applications are processed in 1-2 weeks if discharge goes to an existing city storm sewer catch basin. If discharge is proposed to a new location or to a subsurface tile system, expect 2-3 weeks because the Engineering Division must review stormwater impact. Timeline from application to final sign-off is typically 3-4 weeks for a straightforward replacement or new pit with standard discharge.

Three Farmington Hills sump pump installation scenarios

Scenario A
Replacement pump in existing sump pit, discharge to existing city catch basin — Farmington Hills bungalow, east side
Your 1970s bungalow has a 24-inch diameter sump pit in the southwest corner of the basement. The existing 1/2 hp pump has failed, and you want to install a new pump of the same capacity and discharge the water to the cast-iron drain line that runs to a catch basin in your backyard swale. The existing pit was installed with the house and the discharge path is unchanged. You do not need a permit. This is a like-for-like replacement exempt under Michigan Residential Code. You can hire a plumber or do it yourself (if you're handy with PVC and electrical). The new pump cost is $150–$250, plus $100–$200 for a plumber if needed. Inspection is not required. However — and this is critical — if the old pump is failing because water is entering the pit faster than it can pump out (a sign the pit is undersized or groundwater load has increased), you should mention this to a plumber. An undersized pump that runs constantly will fail again in 2-3 years. If you suspect the load has grown, consider a new-pit permit application to add a larger pit or second pump; that's a $250–$400 investment now versus a $20,000 water intrusion claim in 2025.
No permit required (like-for-like replacement) | Pump cost $150–$250 | Plumber labor $100–$200 | No inspection required | Same discharge location as existing
Scenario B
New sump pit excavation, subsurface perimeter drain tile system, discharge to swale outside foundation — Farmington Hills, north of 13 Mile Road, sandy soil
Your 1990s colonial is experiencing occasional water seepage in the basement after spring melt. The basement has no sump pit. A drainage contractor proposes excavating a 24x24-inch sump pit along the interior perimeter, tying the foundation footer drain tile to the pit, installing a 3/4 hp pump, and discharging through a 1.5-inch PVC line to a swale area 15 feet from the foundation. This requires a permit. The pit is new, and the discharge path (interior drain tile system) crosses the city's stormwater design threshold. You must file a plumbing permit with Farmington Hills Building Department. The application must include a site plan showing pit location, pump model and capacity (calculate GPM from the drain tile and incoming water load), discharge location, and vent (if applicable — standard sump pit vents to air via the pump cover, but confirm with the plumber). The Building Department will review in 5-7 business days. If discharge goes to your own property swale with no outflow to a city storm sewer, approval is straightforward. If the swale drains to a city catch basin or right-of-way, the Engineering Division must sign off, adding 3-5 days. Rough inspection occurs after pit excavation and before drain tile is connected. Final inspection happens after pump installation and before the pit cover is sealed. Total permit cost is $150–$250. Timeline: application to final approval is 2-3 weeks. The pit and pump cost $2,500–$4,500 (contractor labor, materials, and excavation). North-side sandy soil drains faster than clay, so oversizing the pump is less critical here, but the 42-inch frost depth still applies — the discharge line must be buried below frost depth to avoid freezing and clogging.
PERMIT REQUIRED (new pit + drain tile system) | Permit fee $150–$250 | Rough inspection + Final inspection required | Pit excavation + pump installation $2,500–$4,500 | Discharge line must be buried 42+ inches (frost depth) | Site plan and pump capacity calculation required
Scenario C
New ejector pump for below-grade half-bath addition — Farmington Hills, near I-696, replacing old finished basement with new bath
You're finishing your basement and adding a half-bath below the main floor slab. The new toilet, sink, and shower will drain to an ejector pump pit (not a sump pit) because they're below the main sewer line. This always requires a permit in Farmington Hills — it is not optional. The ejector pump must sit in a sealed pit (not open to the sump or perimeter drain system), and it must be vented to the roof through a separate 2-inch PVC vent line per IRC P3108.1. The vent cannot tie into the DWV (drain-waste-vent) system; it's a standalone vent. The pit must have a volume sufficient to hold one full pump cycle (typically 15-20 gallons) plus a backup margin. A water-powered or battery backup pump must be shown on the installation plan. The primary pump must be sized for the fixture load: a half-bath with toilet and sink is typically 4-6 GPM, so a 1/3 hp pump at 20-30 GPM capacity is adequate. You file a plumbing permit with the Building Department; the application includes the pump model, capacity, pit location and depth, vent route (with roof penetration detail), and discharge location (to the sanitary sewer via a junction or the main house drain). Rough inspection occurs before the pit is buried and before the pump is installed. Final inspection occurs after the pump is running and the vent is complete. The inspector will verify vent sizing, pit sealing, backup pump installation, and discharge connection. Total permit cost is $200–$300. Timeline: 1-2 weeks if discharge ties into an existing sanitary line; 2-3 weeks if new sanitary line work is involved. The ejector pump and pit cost $1,200–$2,000 (materials and labor). This is a critical inspection — many homeowners or budget contractors try to vent the pump into the basement DWV or omit the backup, both of which fail inspection and add 1-2 weeks to the project.
PERMIT REQUIRED (below-grade bathroom) | Permit fee $200–$300 | Rough inspection + Final inspection required | Vent must run separately to roof (2-inch line) | Backup pump (water or battery) required | Ejector pump + pit + vent installation $1,200–$2,000 | Timeline 1-2 weeks minimum

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Why Farmington Hills stormwater discharge rules are stricter than nearby cities

Farmington Hills' stormwater ordinance (Chapter 30) reflects the city's experience with combined sewer overflows in the 1990s and a push to reduce stormwater load on the municipal system. Troy and Bloomfield Township allow administrative approval for sump discharge to storm sewers without a full plumbing permit if the discharge is under a certain GPM threshold. Farmington Hills requires a plumbing permit every time. This means your neighbor three miles east in Bloomfield Township might get verbal approval from a contractor to discharge a basement drain to a catch basin without paperwork. In Farmington Hills, that same discharge requires a signed permit, a site plan, and an inspection. The upside: it's safer, more documented, and insurable. The downside: it takes 2-3 weeks instead of a phone call. The city's Engineering Division also maintains records of all sump discharge locations, which helps during flooding events and informs future stormwater master plan updates.

Frost depth and discharge freezing are real hazards here. Farmington Hills' frost depth is 42 inches — deeper than most of Michigan — because the city sits at roughly 900-950 feet elevation on sandy and clay deposits. A discharge line buried only 24 inches (common in warmer states) will freeze solid every January and March when temps fluctuate above and below 32°F. Frozen discharge backs up into the sump pit, pressure builds, and the pump runs continuously until it burns out or trips the breaker. If the pump fails during a spring thaw or heavy rain, the pit overflows and water floods the basement within hours. The city's inspectors will catch an improperly buried discharge line during final inspection and will require remediation — digging up the line and reburying it below 42 inches, or running it through an insulated sleeve, adding $500–$800 to the project. Building the line right the first time (below frost depth or in an insulated conduit) costs $100–$200 extra during installation but saves thousands in emergency repairs.

The city also enforces discharge line slope rules that many homeowners don't know about. The discharge pipe must slope downhill away from the foundation at a minimum 1/8-inch per foot (about 1%) — no flat runs, no uphill sections. A flat or slightly uphill discharge line will trap standing water inside the pipe over winter, freeze, and clog. Again, frozen pipe equals backup into the sump, which equals overflowed basement. Inspectors in Farmington Hills will measure slope with a level during final inspection. If the line is flat, they'll flag it as a deficiency, and you'll have to dig and re-slope the line before the permit is closed. Proper slope is simple if planned during design but a hassle to retrofit.

Backup pump selection: battery vs. water-powered, and why it matters in Farmington Hills

Battery-powered backup pumps have become standard in Michigan basements over the past 10 years because they run independently of the electrical grid — if a storm knocks out power, the backup still works. A typical battery backup (DC-powered, 12V) costs $400–$800 and can pump 500-1,000 gallons before the battery is depleted. For a basement receiving 5-10 GPM of water during a heavy rain, a battery backup can sustain pumping for 1-2 hours, which is usually enough time for the rain to stop or for you to switch to a generator. Water-powered backups (hydraulic or sump-powered) cost $150–$300 and require incoming water pressure to operate — they use the city's water line to generate pressure that drives a piston pump. Water-powered backups are cheaper but add $5–$10 per month to your water bill and don't work if the water is shut off. In Farmington Hills, where spring melt and heavy rain events are seasonal and predictable, a battery backup is the practical choice. If your primary pump fails at 2 AM during a 1-inch rain, the battery backup will handle it until you can repair or replace the primary pump.

The city does not mandate a backup pump for residential sump systems — there's no code requirement — but every experienced plumber and water-damage restorer in Farmington Hills recommends one. A primary sump pump failure costs $500–$1,500 to repair or replace (parts, labor, emergency call-out fee). A basement water intrusion claim costs $15,000–$50,000 (structural drying, mold remediation, flooring and drywall replacement, contents loss). A $600 battery backup is cheap insurance. If you're including a backup pump in your permit application, mention it on the form — it doesn't affect the permit cost, but it's good documentation for insurance purposes. Some homeowner policies offer a small discount (1-2%) if a backup pump is installed and documented.

Installation of a battery backup is straightforward: the backup pump sits in the same sump pit as the primary pump, and the system is configured with a check valve on the primary pump discharge and a separate discharge line from the backup pump that runs to the same location. The battery charger is mounted on a basement wall or shelf and plugged into a GFCI-protected outlet. Test the battery backup monthly by switching the float switch to the backup position and confirming the pump runs. After a heavy rain, check the battery charge level and top it up if needed. Most batteries last 3-5 years before they need replacement ($150–$300). If you're handy, you can replace the battery yourself; a plumber will charge $200–$400 labor for the swap. In a city like Farmington Hills with reliable spring water tables, a battery backup is the difference between a solved problem and a crisis.

City of Farmington Hills Building Department
Farmington Hills City Hall, 31555 West Eleven Mile Road, Farmington Hills, MI 48336
Phone: (248) 871-2600 | https://www.fhgov.com/building
Monday–Friday, 8:00 AM–5:00 PM (closed city holidays)

Common questions

Do I need a permit to replace my existing sump pump with the same model and capacity?

No. A like-for-like replacement of an existing pump in an existing pit is exempt under Michigan Residential Code. You do not need to file a permit, but you should confirm the discharge location is unchanged. If you're upgrading to a larger pump, changing the discharge location, or adding an ejector pump, a permit is required.

What is the difference between a sump pump and an ejector pump?

A sump pump handles groundwater and foundation drainage in a pit open to the perimeter drain system. An ejector pump handles wastewater from below-grade fixtures (toilet, sink, shower) in a sealed pit and must discharge to the sanitary sewer. Ejector pumps require a separate vent line to the roof per IRC P3108.1 and always require a permit. Sump pumps may be exempt if they're replacements, but new sump pits require a permit in Farmington Hills.

Can I discharge my sump pump to my neighbor's yard or to the street?

No. Farmington Hills Chapter 30 stormwater ordinance prohibits discharge to a neighbor's property or to a municipal right-of-way. Discharge must be to your own property swale, to a city-approved storm sewer catch basin (via buried line), or to a designated stormwater system. Discharging to a neighbor's yard is a civil violation and can result in a fine of $500–$1,500.

What is the frost depth in Farmington Hills, and why does it matter?

Farmington Hills' frost depth is 42 inches. Any discharge line running from your sump pit must be buried below 42 inches or run through an insulated conduit to prevent freezing. A frozen discharge line backs up into the sump pit and can cause the pump to fail or the basement to flood during spring thaw or heavy rain. Inspectors verify proper burial depth during final inspection.

Do I need a backup pump for my sump system in Farmington Hills?

Backup pumps are not required by code, but they are strongly recommended. Spring melt and heavy rain are routine in Farmington Hills, and a primary pump failure during a rain event can lead to basement flooding and $15,000–$50,000 in damage. A battery backup costs $400–$800 and will sustain pumping for 1-2 hours if the primary pump fails. Most experienced plumbers include a backup pump recommendation with every sump system installation.

How long does it take to get a sump pump permit approved in Farmington Hills?

If discharge goes to an existing city storm sewer catch basin, 1-2 weeks. If discharge is to a new location or subsurface drain tile system, 2-3 weeks because the Engineering Division must review stormwater impact. Timeline from application to final inspection sign-off is typically 3-4 weeks. Expedited review may be available; contact the Building Department to inquire.

Can an owner-builder pull a sump pump permit in Farmington Hills?

Yes. Homeowners can pull a permit for their own occupied home, but the application requires homeowner certification and acknowledgment that you are responsible for code compliance. Many homeowners hire a licensed plumber because the venting and discharge approval details can be tricky. If you hire a contractor, the contractor pulls the permit.

What happens if my sump pump discharge line freezes?

A frozen discharge line prevents water from exiting the pit. Water backs up into the sump pit, pressure builds, and the pump runs continuously until it overheats and shuts off. If the pump fails during a rain event, the pit overflows and water floods the basement. To avoid freezing, bury the discharge line below 42-inch frost depth or run it through an insulated sleeve. Slope the line downhill at 1/8-inch per foot minimum to prevent standing water inside the pipe.

Do I need a separate vent line for a sump pump, or can it vent into my basement DWV?

Standard sump pits (handling groundwater) do not require a separate vent — they vent to air via the pump cover or a simple air hole. Ejector pumps (handling wastewater from below-grade fixtures) must have a separate 2-inch vent line that runs to the roof per IRC P3108.1. The vent cannot tie into the drain-waste-vent system. Farmington Hills inspectors will flag an improperly vented ejector pump as a deficiency, requiring correction before the permit closes.

What does the permit fee for a sump pump installation cover?

The permit fee typically covers the plan review and two inspections: rough plumbing (before the pit is buried) and final (after pump installation and discharge testing). The fee ranges from $125–$300 depending on job valuation. The fee does not cover the pump, pit, or materials — those are separate contractor costs. If additional inspections are required due to deficiencies, there may be a re-inspection fee of $50–$100 per visit.

Disclaimer: This guide is based on research conducted in May 2026 using publicly available sources. Always verify current sump pump installation permit requirements with the City of Farmington Hills Building Department before starting your project.