Buying on Grassy Key feels like a dream until the first round of utility bills lands in your mailbox. Water, wastewater, and trash work a little differently here than they might where you live now, and that can make budgeting tricky. If you plan to live full-time, visit seasonally, or operate a vacation rental, a clear plan will help you avoid surprises.

In this guide, you’ll learn who provides each service, how billing typically works, what drives costs up or down, and the exact steps to set up or transfer accounts. You’ll also get a simple method to forecast monthly and annual expenses with confidence. Let’s dive in.

Who provides what on Grassy Key

Water: FKAA

Most Grassy Key homes receive potable water from the Florida Keys Aqueduct Authority (FKAA). Service is metered at your property. Your bill usually includes a base charge and a usage charge based on how much water you use. Meters are read on a regular schedule, and you can ask FKAA for your property’s usage history.

Wastewater: City or County, or septic

Many Marathon-area properties connect to centralized sewer. Depending on your parcel’s location, wastewater billing is typically through the City of Marathon utilities or Monroe County utilities. Some properties may still use private septic systems. Confirm the exact setup for your address early in due diligence.

Trash and recycling: Municipal contract or private

Trash and recycling in the Marathon area are often handled by private contractors working under a city or county contract. In some areas, owners subscribe directly with a private hauler. If your home is in an HOA, trash may be included in dues. Pickup schedules, what is included in standard service, and bulk or yard waste rules can vary by location.

How billing works and what drives your costs

Water bill basics

Your FKAA bill typically has two parts: a base charge tied to your meter and a volumetric charge calculated per 1,000 gallons used. Taxes or assessments may apply, and late fees can be assessed if payment is past due. High-use months often reflect lawn irrigation, pool filling or backwashing, and higher occupancy.

Common drivers of higher water costs:

• Seasonal occupancy and vacation rentals increase average use.
• Irrigation systems and pools add significant consumption.
• Hidden leaks, like a running toilet or hose bib drip, can spike usage quickly.
• Rate changes can occur, so request the latest rate sheet when you open an account.

Wastewater billing options

Sewer billing methods vary. Some systems use a flat monthly service fee per dwelling unit. Others base charges on metered water consumption to estimate wastewater flow, sometimes using a winter average or an indoor-use baseline. New connections could involve one-time connection or capacity fees, and you may see facility or treatment surcharges for system improvements.

Key sewer cost factors:

• Flat fee vs usage-based billing affects how you forecast.
• Property type and rate class matter, especially for multi-unit or short-term rental use.
• Special assessments for system upgrades can appear occasionally.

Trash, recycling, and bulk waste

Residential curbside service typically includes weekly refuse pickup and scheduled recycling. Billing can be part of a municipal utility bill, a separate assessment, a private invoice, or covered by your HOA. Extra bags, appliances, and bulk items may incur additional charges. After storms, debris removal may follow special emergency protocols that differ from regular service.

Seasonal patterns and property features

Your budget should reflect how the home is used:

• Full-time vs seasonal: Part-time residency often brings lower water and trash volumes except during visits.
• Vacation rentals: Turnover and higher occupancy can increase all three categories.
• Exterior features: Pools, irrigation, outdoor showers, and fish-cleaning stations add to water use and sometimes trash volume.

Set up or transfer your accounts

Water: FKAA

• What you’ll need: Government ID and proof of ownership, such as a closing statement. Be prepared for a deposit or credit check based on FKAA policy.
• Steps: Contact FKAA to open or transfer the account, confirm your meter number and location, and ask for the last 12 to 24 months of usage for your specific address. Request the current rate schedule and billing cycle.

Wastewater: City of Marathon or Monroe County

• What you’ll need: Proof of ownership and ID. Deposits and paperwork vary by office.
• Steps: Confirm whether your parcel is served by the City of Marathon or Monroe County utilities. Open or transfer service based on their instructions. Ask how your sewer fee is calculated, whether it is flat or usage-based, and whether any assessments apply.

Trash and recycling: Municipal or private

• What you’ll need: Property address, proof of ownership or occupancy, and billing details.
• Steps: Confirm whether trash charges appear on your existing utility bill, are billed separately, or are covered by your HOA. If private, start or transfer service directly with the listed provider. Get the pickup schedule, container sizes, recycling rules, bulk pickup procedures, and hurricane debris protocols.

Build a realistic monthly and annual budget

Start with actual history

Ask FKAA and your wastewater provider for the last 12 to 24 months of records for your address. If trash is city-billed, request that history as well. Usage history shows seasonal peaks and helps you separate base charges from consumption.

Create a baseline and a peak scenario

• Average: Calculate the 12-month average bill for each service.
• Peak month: Note your highest-use month. This is your planning number for high season, extended family visits, or rental peaks.
• Contingency: Add a 10 to 20 percent buffer for leaks, rate updates, or unexpected events like post-storm cleanup.

Include all the right line items

Monthly projections should cover:

• Potable water: FKAA base charge plus usage.
• Wastewater: City or County sewer charge, or a monthly set-aside for septic maintenance.
• Trash and recycling: Municipal fee, HOA-included service, or private subscription.
• Stormwater or municipal assessments: If applicable to your parcel.
• Electricity and propane: Especially important with air conditioning, dehumidifiers, pool pumps, and electric water heaters.
• Internet, phone, and cable: Critical for work-from-home and rental properties.

Plan for one-time and annual costs

• Account deposits when opening new services.
• Connection or capacity fees if you need a new hookup.
• Septic pumping every 3 to 5 years if applicable.
• HOA dues and any reserve assessments.

Simple step-by-step forecasting method

1. Gather 12 to 24 months of actual utility records for the address.
2. Compute the monthly average and identify the peak month for each service.
3. Add known extras for your property, like irrigation, pool operations, or rental turnover.
4. Add a 10 to 20 percent contingency for leaks, rate shifts, or storm-related costs.
5. Review annually and adjust for occupancy, renovations, or feature changes.

If your property uses septic

Some Grassy Key properties use private septic systems instead of central sewer. If that is your setup, you are responsible for routine maintenance and repairs. Lenders may require a septic inspection or pump-out during a sale, and escrow can be used to address issues.

For budgeting, set aside funds annually for inspections and pumping on a 3 to 5 year cycle. Keep records of all maintenance. If you plan to convert to central sewer later, account for possible connection and capacity fees.

Cost-saving and risk reduction tips

• Verify meter location and check for leaks before closing. A running toilet can double a monthly bill.
• Request notarized or official utility statements from the seller. Compare billed usage to occupancy during those months.
• Consider smart leak sensors, especially for rentals or when you are away.
• Evaluate irrigation schedules and look into separate irrigation meters if the property already has one.
• For rentals, teach guests simple water-saving habits and provide clear trash and recycling guidelines.

Quick checklist for closing day

• Confirm water provider is FKAA and that your account is open with the correct mailing and email address.
• Verify whether the property is on city or county sewer, or on septic, and that the correct rate class is applied.
• If on septic, obtain inspection and pumping records from the seller.
• Determine how trash is billed and set service levels that match your occupancy.
• Collect the last 12 to 24 months of utility history for your files.
• Note pickup schedules and bulk trash rules, especially for turnover days or after storms.

FAQs

How do I confirm if my Grassy Key home is on sewer or septic?

• Ask the seller for utility hookup records and recent bills, then confirm with the City of Marathon or Monroe County utilities. County property records can also reflect service type.

Who do I contact to start water service on Grassy Key?

• Contact the Florida Keys Aqueduct Authority. Have your ID and proof of ownership ready, and ask for your property’s recent usage history and the current rate sheet.

How are sewer charges calculated in Marathon and Grassy Key?

• Some systems charge a flat monthly fee per dwelling unit. Others use your metered water consumption to estimate wastewater flow. Ask your provider which method applies to your parcel.

Is trash service included in my utility bill?

• It depends. In some areas, trash is billed through the city or appears as a separate assessment. In others, you subscribe and pay a private hauler directly. If you have an HOA, trash may be included in dues.

Should I budget per person or per property for utilities?

• Start with a per-property baseline using actual history, then adjust for occupancy. Homes used as short-term rentals or with frequent guests will have higher consumption and more trash volume.

Ready to build a budget that supports your lifestyle and your investment goals? Let’s tailor a plan to your property’s location, features, and rental strategy. Let’s connect — schedule your free consultation with Florida Keys Vacation Houses.