Where Does Sandwich's Water Come From?
Water Source
Sandwich Water District groundwater wells (sole source aquifer)
Sandwich, the oldest town on Cape Cod (founded 1637), draws its water from groundwater wells tapping the sole source aquifer. Located on the upper Cape adjacent to Joint Base Cape Cod, Sandwich's wells are vulnerable to PFAS contamination plumes spreading through the aquifer from decades of military firefighting foam use.
What's in Sandwich's Water?
Based on water quality reports, testing data, and environmental assessments, these are the contaminants of concern for Sandwich residents:
PFAS ("Forever Chemicals")
Status: Detected — Groundwater plume
PFAS contamination from Joint Base Cape Cod has been detected in Sandwich groundwater. The town's location on the upper Cape means wells are in the path of migrating contamination plumes from decades of AFFF use.
PFOS (Perfluorooctane Sulfonate)
Status: Above new EPA MCL in some wells
PFOS from military firefighting foam operations has been detected above the new EPA maximum contaminant level of 4 ppt in some monitoring wells. Treatment is being implemented.
Manganese
Status: Naturally elevated
Cape Cod's sandy glacial geology results in naturally occurring manganese in groundwater. Some Sandwich wells have elevated levels that affect taste and appearance.
Nitrates
Status: Monitoring — Septic systems
Like all Cape Cod towns, Sandwich relies heavily on septic systems for wastewater. Nitrogen from these systems is a growing threat to groundwater quality.
Health Risks for Sandwich Residents
According to the EPA and Environmental Working Group (EWG), prolonged exposure to contaminants found in Sandwich's water may increase risk of:
- • Cancer: PFOS and PFOA are linked to multiple cancer types including kidney, testicular, and thyroid cancer
- • Immune Suppression: PFAS exposure reduces immune response effectiveness, particularly concerning for older residents
- • Thyroid Disruption: PFAS interfere with thyroid hormone production, affecting metabolism and energy
📍 Sandwich Local Tip
Sandwich residents — your town's proximity to the base and its well locations mean PFAS is your #1 water concern. The Sandwich Water District posts testing results on their website. If you're in a neighborhood near Route 130 or the base boundary, an RO system isn't optional — it's essential. And if you have a private well? Test it for PFAS immediately.
The Solution: Reverse Osmosis Filtration
Standard pitcher filters (like Brita) are not effective at removing PFAS or most contaminants found in Sandwich's water. Water quality experts recommend a Reverse Osmosis (RO) system that can remove up to 99% of dissolved contaminants.
Why RO Works for Sandwich Water:
- ✓ Removes 99%+ of PFAS, PFOS, Manganese
- ✓ Uses semi-permeable membrane to filter at molecular level
- ✓ Fits under your kitchen sink — no major renovation needed
- ✓ Provides clean drinking and cooking water on demand
- ✓ NSF-certified systems are independently tested and verified
Top Recommended RO Systems for Sandwich
APEC ROES-50
A reliable, no-frills workhorse — perfect for Sandwich families on a budget.
- • 5-Stage filtration system
- • Removes up to 99% of contaminants including PFAS
- • Industry-standard parts (easy, affordable replacements)
- • Excellent long-term track record with thousands of reviews
iSpring RCC7AK
Best for taste — adds healthy minerals back after filtering Sandwich's water.
- • 6-Stage with alkaline remineralization
- • Water tastes like natural spring water
- • See-through housing shows filter condition
- • Top-rated by Sandwich area homeowners
Waterdrop G3P800
The modern, space-saving tankless choice for Sandwich homes.
- • Tankless design saves cabinet space
- • 800 GPD flow rate (fills a cup in seconds)
- • Smart faucet displays real-time water quality
- • Easy twist-and-pull filter changes — no plumber needed
Ready to Install?
Step-by-step DIY installation guide — works for any Sandwich home
View Installation Guide →Frequently Asked Questions — Sandwich Water
Is Sandwich MA water safe to drink?
Sandwich water is actively managed and treated, but PFAS from Joint Base Cape Cod is a significant concern. The town is investing in treatment infrastructure, but home filtration provides an important additional layer of protection.
How does Joint Base Cape Cod affect Sandwich water?
PFAS contamination from decades of military firefighting foam use has spread through the sole source aquifer into Sandwich territory. The sandy Cape Cod soil provides little natural filtration, allowing contaminants to travel far through groundwater.
Does Sandwich have a plan for PFAS?
Yes, the Sandwich Water District has been working with Mass DEP and the military on detection, monitoring, and treatment. Granular activated carbon treatment has been installed or planned for affected wells. However, the scope of contamination means this is a long-term challenge.
Should I use a water filter in Sandwich?
Absolutely. For PFAS contamination specifically, a reverse osmosis system is the most effective home treatment, removing 95-99% of PFAS compounds. This is especially important for families with children, pregnant women, and immunocompromised individuals.
Sources
- • Sandwich Water District Annual Water Quality Report (2024)
- • Massachusetts DEP PFAS Investigation — Upper Cape
- • EPA Joint Base Cape Cod Environmental Investigation
- • Cape Cod Commission Sole Source Aquifer Report
- • Environmental Working Group (EWG) Tap Water Database