The Best Septic Tank Services in Maryland
We graded 7 companies on seven things customers actually report: satisfaction, reliability, workmanship, value, momentum, track record and how owners handle complaints.
From 36,705 Google reviews of 82 top-rated septic tank services nationwide; 7 of them in Maryland. Updated November 5, 2026.
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Best septic tank services in Maryland for septic system installation
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King & Sons Septic Service, LLCHow Job match is calculatedBuilt only from reviews Google tagged “Septic system installation”:Stars on this job 55%4.91★Number of such jobs 25%47Overall Experts Score 20%98Job match= 93Stars are pulled toward the category average (4.89★) when a company has few tagged jobs, so 3 perfect reviews don’t beat 80 great ones. 4.3★ scores 0, 5.0★ scores full. Volume is compared with the busiest company for this job.93Job match = this company’s ★ on reviews Google tagged “Septic system installation” (shrunk toward the category average when there are few), how many such jobs it has done, and its overall Experts Score.
What customers said about septic system installation
King & Sons Septic Service, LLCI don’t often write a review but these guys deserve the highest ratings! Their communication, professionalism and timely response are above par. Customer service is top notch and bonus: they know what they’re doing!
King & Sons Septic Service, LLCKing and Son Septic installed a new septic system at a 100+ year-old home. They took care of all the details related to getting our septic up to code: inspection, permitting, installation. Is has been our pleasure to work with King and Son. They really know what to do and how to get it done!
King & Sons Septic Service, LLCWe are very pleased with the job that King & Sons did, from scheduling our appointment and their flexibility to their communication about their arrival. Travis was very pleasant and did an efficient job while leaving everything clean. We would highly recommend King & Sons!
King & Sons Septic Service, LLCWe love and appreciate your business so much I have been using you for 25 years and will never stop. We clean our Septic every single year it’s worth it.
King & Sons Septic Service, LLCTHE KING FAMILY KNOWS THEIR BUSINESS! PROFESSIONAL, RELIABLE, FRIENDLY, KNOWLEDGEABLE OF MARYLAND AND MONTGOMERY COUNTY RULES AND LAWS. THIS VISIT INVOLVED DIG AND PUMP SEPTIC TANK AND REPLACE BROKEN OUTLET BAFFLE AND TEE PIPE. HIGHLY RECOMMEND!!
King & Sons Septic Service, LLCSo professional. Our service man provided great feedback to my many questions as a first time septic tank owner. Couldn't ask for better service! Feedback for whatever AI bot generated the incomplete service list below: septic tank pumping service is likely the most common service this company performs.
Overall ratings
Experts Score 0–100Experts Score (0–100)Absolute quality first: recency-weighted star average (≈54%), share of 1–2★ reviews (≈24%), customers’ price verdicts (≈14%), owner replies to critical reviews (≈7%); minus up to 10 points each for complaints flagged in Google review highlights and for a real slide in recent ratings. Hover a company’s score on its page for the full breakdown. and a letter grade per factor (A = top 20% of septic tank services).
| # | Company | ScoreExperts Score (0–100)Absolute quality first: recency-weighted star average (≈54%), share of 1–2★ reviews (≈24%), customers’ price verdicts (≈14%), owner replies to critical reviews (≈7%); minus up to 10 points each for complaints flagged in Google review highlights and for a real slide in recent ratings. Hover a company’s score on its page for the full breakdown. | FactorsFactor grades, in orderSatisfaction (54%): Recency-weighted star average (2-year half-life), shrunk toward the category mean by review volume; the company’s own lifetime average as the prior; absolute: 4.0★ = 0, 5★ = 100.Reliability (24%): How rarely jobs go badly: share of 1–2★ reviews — 60% the last 24 months (or the 20 newest if fewer), 40% all-time; 0% = 100, 15%+ = 0; the category percentile can only raise it.Craft & service (0%): Google review highlights: Quality, Professionalism, Responsiveness, Punctuality — how rarely reviewers flag them as a negative, per review since highlights began; 0% = 100, 5%+ = 0. Subtracted from the score (up to −10), never averaged in — clean highlights are the norm, not a bonus.Value (14%): Customers’ own price verdicts (Great / Reasonable vs Overpriced) and Value highlights; 65% absolute (all “reasonable” ≈ 80, “great” = 100), the category percentile can only raise it.Momentum (0%): Penalises only a real slide: last-12-month average below lifetime (−0.5★ = 0). Still 4.8★+ over the last year, or steady/improving = 100. Subtracted from the score (up to −10), never averaged in.Replies to reviews (7%): How often the owner publicly replies to reviews under 5★ (1–4★). Needs 3+ such reviews, otherwise not counted; 65% absolute (80%+ replied = 100), the category percentile can only raise it.One letter per factor score: A = 80+, B = 60–79, C = 40–59, D = 20–39, F = below 20. | ★Google star rating as shown on Google Maps. | Typical billMedian bill customers of this company reported in their reviews (needs 3+ priced reviews). |
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| 1 | King & Sons Septic Service, LLCRockville, MD | A 98How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%99+54Reliability 24%99+24Value 14%100+14.1Replies to reviews 7%77+5.4Experts Score= 98Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAB | 4.99 | $292 |
| 2 |  Environmental SepticRockville, MD | A 96How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 59%96+56.3Reliability 26%94+24.5Value 15%99+15.1Craft & service penalty99−0.1Experts Score= 96Not enough data for replies to reviews; its weight is shared by the others.Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAA– | 4.93 | $295 |
| 3 |  Heil Plumbing & HVACRockville, MD | A 95How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%96+52.4Reliability 24%96+23.3Value 14%98+13.9Replies to reviews 7%78+5.5Craft & service penalty96−0.4Experts Score= 95Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAB | 4.96 | $608 |
| 4 |  Service Force PlumbingRockville, MD | A 94How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%93+50.7Reliability 24%93+22.5Value 14%98+13.9Replies to reviews 7%100+7.1Experts Score= 94Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAA | 4.94 | $642 |
| 5 |  Service Force PlumbingRockville, MD | A 90How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%90+49.1Reliability 24%81+19.6Value 14%100+14.1Replies to reviews 7%100+7.1Experts Score= 90Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAA | 4.93 | $447 |
| 6 |  Sky PlumbingRockville, MD | A 81How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%85+46.4Reliability 24%77+18.7Value 14%100+14.1Replies to reviews 7%65+4.6Craft & service penalty88−1.2Momentum penalty88−1.2Experts Score= 81Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | ABAAAB | 4.86 | — |
| 7 |  Roto-Rooter Plumbing & Water CleanupRockville, MD | B 73How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%80+43.6Reliability 24%74+17.9Value 14%50+7.1Replies to reviews 7%100+7.1Craft & service penalty87−1.3Momentum penalty82−1.8Experts Score= 73Grade B: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | ABACAA | 4.80 | $786 |
What jobs cost
What customers paid, from the price Google asks reviewers to report.
| Job | Low25th percentile: 1 in 4 customers paid less than this. | TypicalMedian of the bill customers reported in their Google review (Google asks reviewers for a price range; we use the middle of each range). | High75th percentile: 1 in 4 customers paid more than this. | FairOf customers who rated the price, the share who chose “Great price” or “Reasonable” rather than “Overpriced”. |
|---|---|---|---|---|
| Drain cleaning | $228 | $328 | $493 | 97% |
| Plumbing pipe repair | $322 | $493 | $1.1k | 97% |
| Toilet repair | $216 | $351 | $593 | 95% |
| Plumbing leak detection | $104 | $264 | $618 | 96% |
| Sewer cleaning | $271 | $379 | $556 | 98% |
| Water heater installation | $1.2k | $1.9k | $2.4k | 97% |
| Plumbing leak repair | $271 | $454 | $1.1k | 95% |
| Faucet repair | $295 | $429 | $680 | 97% |
| Sewer repair | $393 | $1.2k | $2.1k | 98% |
| Faucet installation | $314 | $529 | $845 | 93% |
| Outdoor plumbing system repair | $328 | $529 | $1.2k | 98% |
| Shower repair | $161 | $317 | $466 | 97% |
Septic Tank Services in Maryland at a glance
How the 7 septic tank services we rated in Maryland compare, and what customers praise most.
Experts Score grades
A = score 80+, F = below 20.
- Grade A686%
- Grade B114%
- Grade C00%
- Grade D00%
- Grade F00%
Google ratings
Average stars per company.
- 4.90★ and up571%
- 4.80–4.89★229%
- 4.60–4.79★00%
- Below 4.60★00%
What customers praise
Share of Google review highlights.
- Quality6,91520%
- Professionalism8,11424%
- Responsiveness7,28221%
- Punctuality6,65120%
- Value5,04215%
Was the price fair?
All price verdicts left with reviews.
- Great price1,53527%
- Reasonable3,54462%
- Overpriced2104%
- Not sure4247%
Price verdicts by year
Share calling it great / reasonable / overpriced.
How we grade
Satisfaction (54%) — Recency-weighted star average (2-year half-life), shrunk toward the category mean by review volume; the company’s own lifetime average as the prior; absolute: 4.0★ = 0, 5★ = 100.
Reliability (24%) — How rarely jobs go badly: share of 1–2★ reviews — 60% the last 24 months (or the 20 newest if fewer), 40% all-time; 0% = 100, 15%+ = 0; the category percentile can only raise it.
Craft & service (penalty, up to −10) — Google review highlights: Quality, Professionalism, Responsiveness, Punctuality — how rarely reviewers flag them as a negative, per review since highlights began; 0% = 100, 5%+ = 0. Subtracted from the score (up to −10), never averaged in — clean highlights are the norm, not a bonus.
Value (14%) — Customers’ own price verdicts (Great / Reasonable vs Overpriced) and Value highlights; 65% absolute (all “reasonable” ≈ 80, “great” = 100), the category percentile can only raise it.
Momentum (penalty, up to −10) — Penalises only a real slide: last-12-month average below lifetime (−0.5★ = 0). Still 4.8★+ over the last year, or steady/improving = 100. Subtracted from the score (up to −10), never averaged in.
Replies to reviews (7%) — How often the owner publicly replies to reviews under 5★ (1–4★). Needs 3+ such reviews, otherwise not counted; 65% absolute (80%+ replied = 100), the category percentile can only raise it.