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Best Septic Service Companies in Sunnyside, WA (2026)

5 septic service companies ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →

The short answer

  1. 1

    Best overall in Sunnyside: Cliff's Septic Tank & Sewer, CR Score 60/100; 4.0★ from 49 Google reviews; open Saturdays until 5 PM.

  2. 5

    Best for emergencies (open 24/7): Shadow Mountain Septic and Plumbing LLC, posts 24/7 hours; ranked #5 of 5.

  3. 4

    Most-reviewed: Sunnymex Septic & Drain LLC, 16 Google reviews at 4.1★, the most of 5 ranked after Cliff's Septic Tank & Sewer; ranked #4.

Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank

5 Sunnyside septic service companies are ranked here by CR Score, from ten published factors. 1 is open 24/7, 4 open Saturdays and 3 open Sundays, based on posted hours. The median Google rating is 4.1★ across 5 rated businesses.

Top 5 septic service companies in Sunnyside at a glance

Top 5 septic service companies in Sunnyside at a glance
RankBusinessCR ScoreGoogle ratingBased inHoursBest for
1Cliff's Septic Tank & Sewer604.0★ (49)SunnysideSatOverall
2Sunnymex Septic & Drain, LLC544.3★ (12)SunnysideSat · Sun · Evenings—
3SunnyMex Septic & Drain LLC533.9★ (7)Grandview, 7 mi away——
4Sunnymex Septic & Drain LLC524.1★ (16)Prosser, 13 mi awaySat · Sun · EveningsMost reviews
5Shadow Mountain Septic and Plumbing LLC514.8★ (16)West Richland, 25 mi away24/7Emergencies

The 5 best septic service companies in Sunnyside, ranked

Ordered by CR Score, a 0–100 score from ten published factors. Paid placement never changes the order.

  1. Ranked #1 in Sunnyside

    #1 Cliff's Septic Tank & Sewer

    Based in Sunnyside

    60/100CR Score

    Ranked #1 because of its Google rating and review volume: 4.0★ from 49 Google reviews, the most in Sunnyside.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 4.0★ from 49 Google reviews
    Hours
    Mon–Sat 7:30 AM–5 PM · Sun closed
    Address
    1536 Sunnyside Mabton Rd, Sunnyside, WA 98944
    View profile for Cliff's Septic Tank & Sewer(509) 837-4060

How we ranked Sunnyside septic service companies

We scored 5 Sunnyside septic service companies on ten factors, weighted as shown. A business is ranked when its trade is confirmed and it has 3 or more Google reviews or a claimed profile. A business with no Google reviews scores zero on rating, review volume and recency. Other unknown factors are left out, not counted as zero. Scores last refreshed November 3, 2026.

Paid placement never changes a rank or score. Featured businesses are paid, labelled, limited to 3 and shown above the ranking, outside it.

Read the full method: formula, sources and exclusions

CR Score factors and weights
FactorWeightComputed fromIn Sunnyside data
Reputation25%Google star rating, adjusted for how many reviews back itMeasured
Credentials15%Active state license, bond and workers’ comp on fileNot yet collected
Review volume10%Number of Google reviews, compared with the most-reviewed business on the listMeasured
Recency5%Share of reviews from the last 12 monthsNot yet collected
Availability5%Weekly open hours, Saturday, Sunday, 24/7 or same-dayMeasured
Trade focus10%How clearly the business does this trade (its Google category and name)Measured
Proximity5%Based in the city scores highest, less the farther away it isMeasured
Claimed profile10%The business has claimed its ContractorsRanked profile (free or paid earn the same)Measured
Partnered5%The business links to ContractorsRanked from its own website with our badge, checked periodicallyMeasured
ContractorsRanked reviews10%Verified customer reviews collected by ContractorsRanked: their rating and how many there areMeasured

Septic service companies in Sunnyside: frequently asked questions

Who is the best septic service company in Sunnyside?

By CR Score, the highest-ranked septic service company in Sunnyside, WA is Cliff's Septic Tank & Sewer with a CR Score of 60/100. It has 4.0★ from 49 Google reviews. It is open Saturdays until 5 PM. Sunnymex Septic & Drain, LLC (#2) and SunnyMex Septic & Drain LLC (#3) follow. We ranked 5 septic service companies on ten factors, last updated November 3, 2026.

How many septic service companies are there in Sunnyside?

ContractorsRanked ranks 5 septic service companies serving Sunnyside, WA. 2 of them are based in Sunnyside; the rest serve it from nearby towns. Counts are as of November 2026.

Which septic service companies in Sunnyside are open 24/7?

1 ranked septic service company in Sunnyside posts 24/7 hours. The highest-ranked is Shadow Mountain Septic and Plumbing LLC (#5). Hours come from each business's Google listing as of November 2026, so call to confirm.

Which septic service companies in Sunnyside work on weekends?

4 of 5 ranked septic service companies post Saturday hours and 3 post Sunday hours. The highest-ranked open Saturdays are Cliff's Septic Tank & Sewer (#1), Sunnymex Septic & Drain, LLC (#2) and Sunnymex Septic & Drain LLC (#4). Posted hours are office hours; crews may book weekend jobs separately.

What Google rating do Sunnyside septic service companies have?

The median Google rating among 5 rated septic service companies in Sunnyside is 4.1★, with a median of 16 reviews. Cliff's Septic Tank & Sewer has the most, 49 reviews, and ranks #1. We adjust ratings for review count, so a few five-star reviews cannot top the list.

How does ContractorsRanked rank septic service companies?

Each septic service company gets a 0–100 CR Score from ten published factors, led by reputation (25%), credentials (15%), review volume (10%) and trade focus (10%). A business with no Google reviews scores zero on rating, review volume and recency; other factors we cannot measure are left out. Only businesses with a confirmed trade and 3 or more reviews, or a claimed profile, are ranked.

Do septic service companies outside Sunnyside count in this ranking?

Yes, if they are within 25 mi of the Sunnyside city center, our service radius for septic service companies. Each listing shows where the business is based and how far away it is. Proximity is 5% of the CR Score, so a nearby business gets a small edge.

Can septic service companies pay to rank higher on ContractorsRanked?

No. The CR Score never reads payment status, and this ranking has 0 paid placements. Up to 3 Featured businesses may appear above the list, labelled Featured and showing their honest rank.

Update log for Sunnyside

  1. November 2026: CR Scores recalculated for 5 septic service companies serving Sunnyside.

More septic service companies and Sunnyside pages

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